-
L.R. Jaroszewicz, Z. Krajewski, A. Kieżun, T. Niedziela, "Application of interferometric measurement of Doppler
effect for testing rotation elements", SPIE, 4185, (2000), 512-515
A novel idea of laser Doppler velocimetry application for testing rotation elements is presented. The presented system uses stable interferometric measurement of Doppler effect by new modified one-reflection fiber-optic Fabry-Perot interferometer.
Keywords: interferometry, fiber-optic sensor, velocimeter -
L.R. Jaroszewicz, A. Kieżun, R. Swiłło, "A novel all-fiber ellipsometer", IEICE Trans. on Electron.,
vol. E83-C, 3 (2000), 384-390
In the paper, a theoretical and experimental investigation of a new type of the
in-line optical fiber ellipsometer is described. The discussed device, based on the Sagnac
interferometer, has the possibility to detect the changes of full polarisation state. The
detection of the polarisation state in real time by a system containing standard single-mode
fiber and an appropriate applied modulation technique is a new system property.The device
uses interferometric measurement technique based on the fourth Fresnel-Arago's condition,
which secures very good system accuracy and stability, also presented in the paper.
Keywords: interferometry, fiber-optic sensor, velocimeter -
A. Kieżun, L.R. Jaroszewicz, "In-line fiber-optic ellipsometer for the sensors application", Opto-Electron. Rev.,
8, (2000), 175-180
The theoretical and experimental analysis of a new fiber-optic ellipsometer in the polarimetric configuration is presented. The main idea of the system operation is based on controlled birefringence introducing on a piece of standard single-mode fiber. An estimation of the real-time changes in polarisation state parameters and the ellipsometer measurement have been done for the known induced birefringence. In the paper, the research of the constructed in-line system as a new ellipsometer detection system for the fiber-optic sensor application is also presented.
Keywords: ellipsometer, polarimeter, fiber-optic sensor -
L.R. Jaroszewicz, A. Kieżun, R. Swiłło, "Sensing applications of fiber-optic Sagnac interferometer",
Opt. Appl., 29, (1999), 139-162
The different possibilities of an application of the fiber-optic Sagnac interferometer as the sensor of physical fields are presented. The applications of the Sagnac interferometer as an optical gyroscope for an investigation of slow-speed rotational platforms and a construction of distributed security system are described. The possibilities of an application of modified system for measurements of nanometer vibrations and parameters of the in-line fiber-optic polarizer, phase and polarisation modulator are also presented. Finally, the possibility to use the Sagnac interferometer as the fiber-optic ellipsometer is described.
Keywords: fiber-optic sensor, interferometry, polarimetry -
L.R. Jaroszewicz, "The visualisation of different fiber-optic loop interferometer applications work by applying 3D
Mathematica graphics", International Mathematica Symposium IMS'99, 23-25.08.1999, Linz, Austria
The usefulness of the Mathematica 3D visualisation and animation for investigation of fiber-optic loop interferometer in different engineering applications work is presented. The Jones' matrix calculus has been used for description as fiber-optic elements as all interferometric systems. Such uniform description gives a possibility to obtain analytical relations, which depend on fundamental system parameters. Unfortunately, these relations are usually too complicated for physical interpretation. The possibility of their analyse by the animated 3D graphics is also shown in the present paper.
Keywords: numerical methods, visualisation, fiber-optic interferometry -
L. R. Jaroszewicz, A. Kieżun, R. ¦wiłło, "A novel all-fiber ellipsometer", SPIE, 3746, (1999),
292-295
A new concept of in-line optical fiber ellipsometer in two different configurations of classical polarimeter and Sagnac interferometer is presented. The possibility of detection the changes of full polarization state in the systems contained standard single-mode fiber, by appropriate applied modulation technique is discussed.
Keywords: fiber-optic sensor, interferometry, polarimetry -
A. Kieżun, L.R. Jaroszewicz, "Polarimetric detection set-up for fibre sensors", Molecular and Quantum
Acoustics, 20, (1999), 109-114
The idea of the polarimetric detection system presented in this paper is a new approach to problem of state of polarisation measurements. The system controlled by computer consists of tunable retarder, analyzer, and detector. Theoretical considerations have been confirmed by an experiment, where twisted single-mode fiber has been used.
Keywords: fiber-optic sensor, ellipsometry, polarimetry -
L.R. Jaroszewicz, A. Kieżun, R. Swiłło, "Fiber-optic ellipsometer on the base of Sagnac
interferometer", SPIE, 3744, (1999), 452-458
A new type of the in-line optical fiber ellipsometer based on the Sagnac interferometer is described. The possibility of the detection of the changes of full polarisation state in this system containing standard single-mode fiber by an appropriate applied modulation technique is discussed. The device uses interferometric measurement technique based on the fourth Fresnel-Arago's condition, which secures very good system accuracy and stability. The results of investigations of the system are presented.
Keywords: fiber-optic sensor, ellipsometry, polarimetry, interferometry -
A. Szelmanowski, L.R. Jaroszewicz, "Usefulness of the fiber-optic Sagnac interferometer for stability
analysis of slow-speed rotation test-stands", SPIE, 3745, (1999), 324-330
Experimental results of the usefulness of the fiber-optic Sagnac interferometer for a measurement of angular position as motion uniformity of slow-speed rotating objects are presented. The system contains GS-13P/SR device with modified signal processing unit. The results of an investigation of this system, and their application for rotation angle and uniformity motion of object in inertial space are shown. A new slow-speed platforms generate constant angular motion (M19-03 stand made by COBRABiD Optica) and harmonic variable motion (STW-1 stand made by AFIT) have been used as forces source. The Fourier (FFT) and wavelets (FWT) analyses have been used as mathematical description of GS-13P/SR application for technical diagnostic of slow-speed platforms.
Keywords: fiber-optic gyroscope, slow-speed velocity investigation, mechanical construction examination -
A. Szelmanowski, L.R. Jaroszewicz, "Analysis of the reasons of angular velocity oscilations in single-stage
slow-speed platform", J. Tech. Phys., 39, 2, (1998), 61-74
Theoretical and experimental results of studies on stability of slow-speed motion generated by a single-stage rotating platform designed for investigation of angular velocity meters are presented. On the simulation basis, the possibilities to obtain smooth rotary motion have been analysed for very low angular velocity, of the order of Earth revolution velocity. In the experimental part, an application of fiber-optic gyroscope enabling experimental verification of the theoretical results obtained is presented.
Keywords: fiber-optic gyroscope, slow-speed velocity investigation, mechanical construction examination -
A. Szelmanowski, L.R. Jaroszewicz, "Stability analysis of two-stage backward slow-speed platform",
Machine Dynamics Problems, 22, (1998), 93-113
The results of theoretical and experimental studies on a stability of a rotary motion generated by a two-stage slow-speed platform are presented. This platform has been designed for a diagnostics of mechanical sensors of an angular velocity. On the simulation studies basis the possibility to obtain smooth rotary motion for very low angular velocities, order of the Earth revolution, has been analysed. In the experimental part an application of fiber-optic gyroscope as a system for the experimental verification of obtained theoretical results is presented.
Keywords: fiber-optic gyroscope, slow-speed velocity investigation, mechanical construction examination -
A. Szelmanowski, L.R. Jaroszewicz, "Application of fibre optic gyroscope for quality research of
slow-speed angular rotation", SPIE, 3730, (1998), 8-12
Theoretical and experimental results of studies on a stability of slow-speed motion generated by different type rotating platforms designed for an investigation of angular velocity meters are presented. An application of fiber-optic gyroscope with sensitivity 0.2 deg/h and drift range of Earth rotation give possibility for measurement real rotation generated by platforms in their all work range. Especially, a possibility of a measurement in the lowest range is a new possibility. The method presented in paper has given also a possibility to investigate error sources of generated rotation velocity.
Keywords: fibre optic gyroscope, slow-speed velocity investigation, mechanical construction examination, simulation -
L.R. Jaroszewicz, A. Kieżun, "Measurement of nanometer vibrations by fiber-optic loop interferometer",
IOP Publishing, Bristol & Philadelphia, England, 323-328, 1997
An application of a measuring system based on fibre optic loop interferometer for measurements of nanometer amplitude vibrations is described. Due to suitable system configuration, the complex measurement of vibration amplitude in the range from 0.1 to 120 kHz with a resolution order of 100 Hz has been obtained. The described system may be adopted for the measurement of polarization-phase characteristics of fiber-optic modulators.
Keywords: fiber-optic device, interferometry, polarisation -
L.R. Jaroszewicz, "Applications of Mathematica for investigate of the polarisation role in fiber
optic interferometers", CM Publishing, Southampton, England, 283-290, 1997
The possibility of visualisation and animation of polarization influence on fiber-optic elements and interferometer work by Mathematica is presented. The above description based on application for any fiber optic elements and optical part of interferometer systems the Jones' matrix calculus. The simply method of study the differences and similarities in a description of particular group of interferometers by Mathematica is showed. The possibilities analyse of a reduction of polarization effect on particular fiber-optic elements and interferometers are the main advantage of this Mathematica application.
Keywords: numerical methods, visualisation, fiber-optic interferometry, polarisation -
L.R. Jaroszewicz, A. Szelmanowski, "Application of fibre optic gyroscope for quality research of
angular rotation in slow-speed platforms" SPIE, 3479, (1997), 284-293
Theoretical and experimental results of studies on a stability of slow-speed motion generated by different type rotating platforms designed for an investigation of angular velocity meters are presented. On the simulation basis, the possibilities to obtain smooth rotary motion have been analyzed. The main attention has been paid to low angular velocity, order of Earth revolution velocity. Slow-speed platforms constructed nowadays exhibit many technical problems caused mainly by wide range of revolution velocity. Very often angular velocity generated by them exhibits large disturbances caused by mechanical principle of action. These disturbances cause oscillations of instantaneous velocity, which increase for decreasing mean value of generated angular velocity of rotary motion. In theoretical simulation, the role of sub-assemblies workmanship has been discussed. Moreover, the effect of this workmanship on the level of generated rotation velocity oscillations has been estimated. In experimental part, an application of fibre optic gyroscope enabling experimental verification of obtained theoretical results is presented. According this application, the instabilities of angular velocity produced by different rotation platforms have been well visualized and measured.
Keywords: fibre optic gyroscope, slow-speed velocity investigation, mechanical construction examination, simulation -
A. Kieżun, L.R. Jaroszewicz, R. ¦wiłło, "Computer-aided automatic polarimeter", SPIE, 3094, (1996),
100-104
The theoretical idea describing a new technical solution of a polarimeter designed for measurements of a rotation angle of light polarization plane is presented. The detecting part of a polarimeter consists of a linear phase shifter, an analyzer placed at suitable azimuth behind them and a detector. Phase shift between orthogonal polarized waves is controlled by a computer. A change of a detector signal is assigned to a change of a phase shift on linear phase shifter. In this way, a location of light polarization plane before linear phase shifter may be measured. Theoretical considerations have been corroborated by experimental results.
Keywords: polarization, polarimeter, automatic measurements. -
L.R. Jaroszewicz, "Polarisation role in fiber-optic interferometers" SPIE, 3094, (1996), 204-216
An extensive description of fiber-optic interferometer with any optical configuration basing on Jones' matrix calculus is presented. An introduction of a special classification of interferometric systems has made possible to model differences and similarities in a description of particular group of inteferometers. For modeling purposes, a description of optic fibers by means of Kapron's rule of equivalence has been introduced. Possibilities of a reduction of polarization effect on particular systems are also described.
Keywords: interferometry, optical fiber, polarization, fiber-optic sensors -
L.R. Jaroszewicz, S. Kłosowicz, K.Czupryński, A. Kieżun, E. Nowinowski-Kruszelnicki, T. Niedziela,
"Tunable liquid crystal fiber-optic polarizer and related elements", Mol. Cryst. Liq. Cryst. 368 (2001), 17-24
A new in-line type tunable liquid crystal fiber-optic device is presented. The main idea is to obtain anisotropic waveguide structure based on biconically tapered isotropic fiber core and anisotropic liquid fiber clad. As the liquid-crystalline clad, the nematic mixture 1110-10C3 made by Dabrowski's group has been used. The special construction of a device with square cross-section secures a possibility to change molecular orientation of the liquid-crystalline clad by external field. Thus, different polarising action has been obtained depending on fulfilment waveguide condition of the structure.
Keywords: liquid crystal devices, tapered optical fiber, polarisation phenomena, tunable optical devices, electro-optical effect -
L.R. Jaroszewicz, A. Kieżun, N. Pałka, "Fiber-optic polarizer with D-type waveguide", SPIE, 4239,
(1999), 217-222
The results of fiber-optic polarizer preparing in base of a fused biconical taper technology are presented. A new element of this work is use of a high-birefringence fiber with D-type cladding. The received results have been compared with theoretical investigation obtained for suitable prepared substitute model of polarizer structure. All results ware made for elements working on visible range of light (He-Ne laser).
Keywords: fiber-optic polarizer, technology, metrology -
A Kieżun, L.R. Jaroszewicz, R. ¦wiłło, "In-line fiber-optic biconical polarizer", Opt, Appl., 29,
(1999), 163-169
The construction of in-line fiber-optic polarizer is presented. This element based on the biconical taper structure positioned on a metal layer. The four-layer planar structure has been used for theoretical investigation of polarizer action. Obtained theoretical results have been compared with experimental investigation of manufactured elements. The technological set-up for the polarizer preparation is also shown. The reported polarizers have been made for wavelength 0.633 mm and 1.300 mm. First of them has typically extinction ratio of 25 dB with an attenuation of guided mode of 3 dB. The second one has typical extinction ratio of 30 dB or more, with an attenuation of the desired polarisation of about 2dB.
Keywords: fiber-optic polarizer, biconical taper technology, elliptical core optical fiber -
A. Kieżun, A. Walczak, L.R. Jaroszewicz, E. Nowinowski-Kruszelnicki, "Tunable liquid-crystal retarder
for fiber-optic polarization detection system" IEEE Trans. on Instrum. and Measurement in print
An idea of a new fiber-optic system with detection of full state of polarization is presented. The main advantage of them is an elimination of precise mechanical turning elements necessary in classic polarimetric systems. The above advantages have been achieved by an application controlled by computer tunable liquid-crystal retarder as a main element of polarimeter. The change of a detector signal related to the change of retardation on a liquid-crystal plate allows to obtain parameters of the polarization ellipse. Theoretical model of an action of element used in so called one-constant approximation is presented. Moreover, the rules of a construction, driving and measurements of birefringent properties of this device are described.
Keywords: polarimeter, fiber-optic sensor, tunable retarder, liquid crystal -
A. Kieżun, L.R. Jaroszewicz, A. Walczak, E. Nowinowski-Kruszelnicki, "A direct measurement of
refractive index profile in liquid crystal planar waveguides" SPIE, 3745, (1999), 92-98
The collected results of the refraction index profile measurement in highly anisotropic, tunable liquid crystalline waveguides are presented. The three different liquid crystal substances have been examined. Initial orientation of the liquid crystal layer is deformed by an external electric field. The initial orientations have been prepared as twisted and planar for liquid crystal material with positive dielectric anisotropy. In the liquid crystal material with negative dielectric anisotropy as initial has been examined hybrid orientation.
Keywords: liquid crystal waveguide, refractive index profile, fiber-optic sensor, interference -
S.J. Kłosowicz, L.R. Jaroszewicz, E. Nowinowski-Kruszelnicki "Optical effects in polymer-dispersed
liquid crystal-fiber-optic devices", Mol. Cryst. Liq.Cryst., 321, (1998), 323-331
Optical effects in PDLC - fiber-optic systems have been studied. The main attention is devoted to intensity modulation based upon electrically driven transmittance and switching effect based upon grating structure in PDLC films. Obtained results are discussed from application points of view.
Keywords: fiber-optic device, PDLC, light modulators, diffraction gratings -
A. Walczak, A. Kieżun, E. Nowinowski-Kruszelnicki, L.R. Jaroszewicz, "New approach for a direct
measurement of refractive index profile in liquid-crystalline layer", Mol. Cryst. Liq.Cryst., 321, (1998), 430-436
The prism coupler method has been applied to the investigation of refractive index profile (RIP) in liquid crystal (LC) layer. Waveguide modes have been excited in thin LC layer arranged as a planar waveguide. Modal lines of the modes excited in the waveguide are observed as evanescent in dielectric prism by tunnelling effect. Measure position of each modal line provides a mode propagation constant value. In a multimodal waveguide, the set of the propagation constant creates data for RIP determination by means of M-line procedure. The usefulness of the M-line method to the investigations of LC waveguides is illustrated and verified by nematic liquid crystal (NLC) elastic response measurements.
Keywords: liquid crystal waveguide, refractive index profile, prism coupler -
E. Nowinowski-Kruszelnicki, A. Walczak, A. Kieżun, L.R. Jaroszewicz, "Investigation on light
transmission losses in liquid crystal waveguides" SPIE, 3318, (1997), 410-413
The investigation results of the propagation loss due to light scattering in electrically induced channel in planar waveguides are presented. The channel structure was obtained by means of electric driven stripe electrode made by photolithography process. Planar waveguiding cell has been fabricated using ITO/SiO2/polymide-coated glass plate and LC films 20 mm thick. A nematic liquid crystal layer with 90o-twisted nematic orientation was studied. The He-Ne light beam was endfire coupled into an input edge of a waveguide using an objective lens. The propagation loss has been evaluated from the spatial variation intensity of light scattered out perpendicularly to the waveguide surface along the light propagation direction measured with CCD camera. Loss measurements have been made in room temperature. Waveguiding channel effect has been observed above 2.5 Vrms of applied voltage with the loss of about 17 +/- 1 dB/cm. Increased driving voltage up to 100 Vrms reduces the loss to minimum value of 12 +/- 1 dB/cm. As a result of the experiments one may conclude that transmission loss in thick nematic waveguide have bulk character caused by imperfection of molecular alignment.
Keywords: liquid crystal, waveguide, liquid crystal waveguide, nematic waveguide, propagation loss -
A. Walczak, A. Kieżun, E. Nowinowski-Kruszelnicki, L.R. Jaroszewicz, "Application of planar
technique to investigation of liquid crystal"- Electron. & Telecom. Quart., 42, 3 (1996), 335-342
Modified method of prism coupler has been applied to obtain profiles of refractive index of liquid-crystalline film. Due to a special construction of a measuring head, studied film has been applied in form of optical waveguide. Then propagation constants of excited waveguide modes have been measured. On the base of the obtained family of propagation constants, the profile of refractive index has been calculated. These measurements allow obtaining angular distribution of directors in liquid-crystalline film. The examples of experimental results are given for two arrangements of the LC film, namely homogeneous and twisted 90o.
Keywords: nematic liquid crystal, waveguide, prism coupler -
K.A. Cyran, L.R. Jaroszewicz, "Rough Set Based Classification of Interferometric Images",
in Interferometry in Speckle Light: Theory and Applications, ed. Jean-Marc Fournier, Springer 2000, 413-420
The paper describes the pattern recognition system used for classification of interferometric images. The images to be classified are taken at the output of quasi-monomode optical fiber. A change of intermodal interference conditions produced by external pressure of this optical fiber causes the differences in these images. The aim of the system is to recognize the class of external pressure from interferometric image analysis. The proposed recognition system consists of a feature extractor based on computer simulated holographic element and a classifier. For classification the formalism of rough set theory is used. This theory is proven to be useful tool for classification performed on the base of conditional attributes. It is an alternative approach comparing to neural network based classifiers. As a result of data analysis with rough set methodology it is possible to obtain minimum number of minimal decision rules describing the process of classification. Experimental results confirm the overall good performance of the proposed methodology.
Keywords: computer-generated hologram, ring-wedge detector, artificial neural networks, rough sets, evolutionary optimization, pattern recognition, optical fiber sensor -
L. R. Jaroszewicz, K. A. Cyran "CGH-ANN based system in interference pattern recognition", SPIE, 4129,
(2000), 608-615
Interference figures are often subject of interest in subsurface sensing technologies. Proper further processing of them is essential for interpretation of data covered in such images. This interpretation is often possible after recognition of the interference patterns. The article presents pattern recognition system suitable for dealing with interference figures. The system consists of optimized computer-generated hologram used for feature extraction and artificial neural network used as classifier of features. This pattern recognizer was tested with images of intermodal interference occurring in the optical fiber. If this fiber is embedded in the polymer composite material then such subsurface sensor together with mentioned pattern recognition system can be used for determining stress and distortion of that material. Since polymers are wide utilized for different constructions, including airplane wings, presented hybrid system can be used for real time, nondestructive monitoring of working stresses occurring in these constructions. The recognition of critical compressive stress can be therefore an early alarm signal of possible forthcoming danger.
Keywords: signal processing, classification, pattern recognition, computer generated holograms,neural networks -
L.R. Jaroszewicz, K.A. Cyran, T. Podeszwa, "Optimized CGH-based pattern recognizer",
Opt. Appl., 30, (2000), 317-333
A pattern recognition system with the computer-generated hologram used as feature extractor, useful in many applications, is considered in paper. The method of optimization of such extractors, based on modified evolutionary algorithm with elements of rough set theory used to define a proper objective function, is also presented. The theoretical investigations are supported with experimental works for two different applications of optimized system. The applications are examples of a wide area of pattern recognition problems where proper characteristic features are not easy to determine. The obtained results confirm the enhancement of system optimized with proposed method comparing to systems with standard computer-generated hologram.
Keywords: computer-generated hologram, ring-wedge detector, artificial neural networks, rough sets, evolutionary optimization, pattern recognition, optical fiber sensor -
K.A. Cyran, L.R. Jaroszewicz, "ANN-based classifier of features produced by computer generated
holograms", IFAC Workshop on Programmable Devices and Systems PDS-2000, 7-09.02.2000, Ostrawa, Republic of Czech, 97-102
The paper presents the ANN-based pattern recognition system with computer generated hologram (CGH) used as a feature extractor. Features obtained by standard and optimised CGH are classified using multi-layer perceptron network. Experiments with gradient and stochastic learning rules, as well as different hidden layer sizes for this system are presented. The objective in these experiments, were to classify the distortion of quasi-monomode optical fiber from speckle images taken when this distortion occurred.
Keywords: signal processing, neural networks, pattern recognition, classifiers, learning algorithms, optical fiber - K.A. Cyran, L.R. Jaroszewicz, A. Mrózek,"Optical fiber and genetically optimized computer
generated hologram in force detection and classification" - SPIE, 4238, (1999), str. 234-238
Quasi-monomode optical fiber sensors, used as input of systems for external force detection and classification, are widely described in references. Feature extractors in such systems are often based on computer generated holograms (CGH) and classifiers are usually built as artificial neural networks (ANN). The use of CGH instead of ring-wedge detector gives possibility of easy change of ring and wedge sizes. In this paper, we present our method of CGH optimization. This method is based on evolutionary algorithms and elements from rough set theory (RST). The results of classification of features obtained by applying optimized by our method CGH confirm that proposed approach can be successfully used for detection and classification of external force. All what is needed for this purpose is to pass coherent light through quasi-monomode optical fiber, and to place CGH in a focal plane of the lens. As CGH regions are the subject to be optimized to given application and therefore minimized in size, the resulting hybrid optic-digital system can be compact and relatively cheap. The experimental results for classification of generated by optimized CGH features confirmed the good overall quality of the proposed system.
Keywords: fiber-optic sensors, rough set theory, evolutionary optimization, pattern recognition, computer generated holograms -
L.R. Jaroszewicz, T. Podeszwa, A. Mrózek, J. Wolski, "Idea and first results of fiber-optic sensor for
engine estimation condition", SPIE, 4239, (1999), 86-90
A new concept of optical fiber sensor for automatic recognition and classification static images has been presented. The sensor based on a fiberscope connected with appropriate detector, which works also as classifier. The main role of the fiberscope is transmission and magnification of analysed image. Presented system is tested for automatic estimation engine condition based on exploration of metallic fraction gathered from lubricating oil.
Keywords: fiber-optic sensor, machine diagnostic, automatic images recognise -
L.R. Jaroszewicz, K.A. Cyran, S.J. Kłosowicz, A. Mrózek, "Fiber-optic sensor with few-mode speckle
pattern recognise by diffraction method", SPIE, 3744, (1999), 386-393
The construction of the fiber-optic sensor for the recognition of perturbations and results of its studies are presented. As a sensor head, the sample of few-mode optical fiber is used. Changes of intermodal interference condition, caused by external perturbation, have generated changes of output speckle pattern. This output has been concerned as an intensity image and diffraction method has been applied for its recognition. The image feature extraction has been achieved by applying a computer-generated hologram in the Fourier plane of an output image. A size of ring and wedge generated by this hologram has been optimised by using the rough set theory. Then, an artificial neural network has been used to recognise the external perturbation without a necessity of troublesome analysis of intermode interactions. An additional advantage of this solution is the possibility to train the network to eliminate slow environmental perturbations.
Keywords: fiber-optic sensor, intermodal interference, automatic recognise method, neural networks -
I. Merta, L.R. Jaroszewicz, A. Kieżun, "An application of the Fourier transform for fiber-optic
sensor recognition", Opt. Appl., 29, (1999), 171-179
The construction of the fiber-optic sensor of external perturbations and results of its studies are presented. As a sensor head, the sample of two-mode optical fiber is used. Changes of intermodal interference condition, caused by external perturbation, generated changes of output speckle pattern. This output has been concerned as an intensity image and diffraction method has been applied for its recognition. For this reason, the ring-wedge photodetector has been placed in the Fourier plane of the image studied. The digital signal generated by this detector has been processed by software neural network. As the effect of suitable process of network training, a possibility of the perturbation recognition has been obtained without a necessity of troublesome analysis of intermode interactions.
Keywords: fiber-optic sensor, speckle pattern recognise, neural network application -
L.R, Jaroszewicz, I. Merta, "Fiber optic external perturbation sensor with analysis of intermode
coupling by ring-wedge photodetector", SPIE, 3730, (1998), 13-17
The construction and experimental results of fiber-optic sensor using the ring-wedge photodetector is presented. As sensor head, the sample of quasi-monomode optical fiber is used. Changes of intermodal interference condition, due to external perturbation, generated changes of output speckle pattern. Those pattern differences are automatically recognized by neural processing. The pattern for neural processing is generated by suitable placed ring-wedge photodetector system.
Keywords: fiber-optic sensor, pattern recognise, neural network -
L.R. Jaroszewicz, I. Merta, A. Kieżun, "Fiber-optic external perturbation sensor with ring-wedge
photodetector", SPIE, 3555, (1998), 337-342
The construction of the fiber-optic sensor for the recognition of perturbations and results of its studies are presented. As a sensor head, the sample of two-mode optical fiber is used. Changes of intermodal interference condition, caused by external perturbation, generated changes of output speckle pattern. This output has been concerned as an intensity image and diffraction method, known from automatic image recognition, has been applied for its recognition. For this reason, the ring-wedge photodetector has been placed in Fourier plane of the image studied. The digital signal generated by this detector has been processed by software neural network. As the effect of suitable process of network training, a possibility of the perturbation recognition has been obtained without a necessity of troublesome analysis of intermode interactions. An additional advantage of this solution is the possibility to train the network to eliminate slow environmental perturbations.
Keywords: fiber-optic sensor, pattern recognise, neural network. -
T. Niedziela, A. Stankiewicz, L.R. Jaroszewicz, I. Merta, "Method for extraction of contours for
identifying characteristic information in noisy images", Opt. Appl., 28, (1998), 81-93
The problem of extraction of a contour from a highly noised image is discussed. The method for contour extraction is known in literature as regularisation with discontinuities. This method, when applied to highly noised images, gives good results and, moreover, may be adapted to a simple cellular neural network. This possibility allows performing real-time contour extraction. The idea of the method of regularisation with discontinuities is presented and one of its variants for the case of temperature noise is used for illustration. The method discussed is examined by means of different functions of the extinction noise temperature.
Keywords: image regularisation, contour extraction, temperature noise, neural network -
T. Niedziela, A. Stankiewicz, L.R. Jaroszewicz, "Contour extraction from images with diferent spectral
ranges", SPIE, 3730, (1998), 32-25
The work presents a method for extraction of a thin regularized contour enabling simultaneous processing of the scene images made in various spectral ranges. The method presented can be easily accomplished in the form of a cellular neural network. The basis of the method is the energy function of states of original images, fitted images, and the contour created, which are defined adequately. Optimization of the fitted images and the contour extracted is made with the gradient decrease method in relation to their states. The energy of the states of images is represented as a sum of a few terms corresponding to various effects of the method. The energy of states subjected to the minimization process determines the architecture and dynamics of the neural network.
Keywords: image regularisation, contour extraction, neural network -
A. Stankiewicz I. Merta, L.R. Jaroszewicz, "The edge regularisation of noised image method", 4th
International Workshop on Cellular Neural Networks and Their Applications CNNA'96, 24-26.06.96 Seville, Spain, 207-211
This work proposes a model of extraction and regularisation of edge of noised image defined as local maximum of gradient. The model is based on defining local dependencies between pixels of image, the so-called pattern and step, dynamic approximation of value of brightness of individual pixels. The dynamics of the model is defined by an adequately constructed function of cost (further on called energy, due to an analogy with potential energy). Energy is specified from the use of the sum of adversities of scalar products of the neighbouring vectors of gradient. This process can be easily implemented in a cellular neurone network of a suitable design. Regularization of image is an important phase of image processing, among others when applied to recognition.
Keywords: images recognise, cellular network, contour regularisation -
L. R. Jaroszewicz, P. Marć, A. Kieżun, "In-line fiber-optic ellipsometer with full polarization
analysis in real time", SPIE, 4481, (2001), 141-148
The analysis of a new in-line fiber-optic ellipsometer in the polarimetric configuration is presented. The main idea of the system operation is based on controlled birefringence modulation on a piece of standard single-mode fiber followed by an identification of the input polarization parameters change by a suitable detection of different harmonics of the output signal. The paper presents results of system investigation for polarized and partially polarized light. Finally, some experimental results of constructed system action are presented and discussed. -
L.R. Jaroszewicz, "Polarisation behaviour of different fiber-optic interferometer configurations
under temperature changes", Opt. Appl., 31, (2001), 399-423
The paper presents the theoretical investigation of temperature influences on the fiber-optic interferometer action for different configuration. On a basis of the phenomenological description of interference phenomena in the optical fiber, the role of coherence and polarisation in the fiber-optic interferometer are discussed. Obtained final conclusions are used in the main part of paper connected with an analysis of temperature influence on different fiber-optic interferometer configuration action. This analysis is made in the Jones matrix formalism applied for interferometers in minimal functional configuration. Finally, the suggestion of using the fiber-optic ellipsometer for polarisation controlling is suggested and described. -
L.R. Jaroszewicz, R. ¦wiłło, A. Kieżun, "Fiber-optic Sagnac ellipsometer", OECC/IOCC 2001 Conference
incorporating ACOFT, 1-5.07.2001, Sydney, Australia, 242-244
In the paper, a theoretical and experimental investiga-tion of the fiber-optic Sagnac ellipsometer (FOSE) is described. A new system property is the possibility to detect, in real time, the changes of the polarisation state for partially polarised light. The presented device uses interferometric measurement technique based on the fourth Fresnel-Arago's condition (FAC-IV), which secures very good system accuracy and stability. -
S. ¦wiłło, L.R. Jaroszewicz, "Automatic shape measurement on base of static fiber-optic fringe projection
method", 5th Intern. Conference on Engineering Design and Automation EDA 2001, Las Vegas, USA, 5-8.08.2001, 272-277
A new shape measurement method, which combines the fiber-optic interferometric fringe projection method and effective numerical spatial phase unwrapping method, is proposed. Simplicity of system arrangement determining low set-up cost is the main advantage of the method presented. The presented theoretical description is based on especially constructed method of automated analysis of the fringe patterns carried by the suitable used Fourier transform and phase unwrapping. The obtained theoretical results contain some error analysis related to the accuracy of CCD camera possible to use. An experimental result is presented for the measurement of a real object and shows the validity of the proposed method. -
L.R. Jaroszewicz, "Optical fiber Sagnac interferometer as a sensor for environmental interaction" 14th
School of Optoelectronics Fotonics in Information Processing FIP, 7-11.11.2000, Stare Jabłonki, 275-285
The detection possibilities of different physical environmental interactions by fiber-optic interferometer in the Sagnac configuration are presented. All investigations based on basic comparison of a bulk and a fiber-optic interferometric interaction. The presented in paper examples have been developed in MUT as different sensor devices designed for investigation of rotation moving, in-line fiber-optic element measurements, detection the state of polarisation of light beam and secure system for external object protection. -
K.A. Cyran, L.R. Jaroszewicz, T. Niedziela, "Neural network based automatic diffraction pattern
recognition", Opto-Electron. Rev., 9, (2001), 301-307
The paper presents automatic recognition of images using the diffraction pattern sampling. This method, based on properties of Fourier transform, utilizes special shapes of sampling element and gives the possibility to deal with data invariant with respect to typical transformation (shift, rotation and scaling) of the input images. Furthermore, if computer-generated hologram is used as feature extractor, instead of commercially available ring-wedge detector, then the process of feature extraction can be optimized with, proposed by authors, method. The method uses rough set theory for objective function definition and stochastic evolutionary algorithms for space search. The features obtained by optimized sampling of the diffraction pattern are the input data for the semantic classifier. Since noise present in images has got typically Gaussian distribution, therefore the classification should be made in the model with statistical uncertainty. For this purpose artificial neural network is used. The presented method is illustrated with experiments of speckle pattern recognition performed with optimized and standard computer-generated holograms. The experiments confirmed good overall accuracy of the optimized system outperforming the results obtained for standard one by a factor of two to five. -
L.R. Jaroszewicz, K.A. Cyran, T. Niedziela, "Optimised holographic ring-wegde detector in semantic
pattern recognition system", 7th World Multiconference on Systematics, Cybernetics and Informatics SCI-2001, Orlando, USA,
22-25.07.2001, Proc. vol. VI, 96-101
The paper presents the semantic pattern recognition system with optimized holographic ring-wedge detector (HRWD) used as a feature extractor. Features obtained on the output of optimized HRWD are converted, digitized and classified using multi-layer perceptron network or rough set based classifier. The system was used in experiments that verified the recognizing quality of it. The objective in these experiments, was to classify the distortion of quasi-monomode optical fiber from speckle images taken for different distortion conditions. The process of design of optimized HRWD is also given together with HRWD masks obtained as the result of the design. -
K.A. Cyran, L.R. Jaroszewicz, T. Niedziela, "Automatic image recognition based on diffraction
method and artificial neural network" 14th School of Optoelectronics Fotonics in Information Processing FIP, 7-11.11.2000,
Stare Jabłonki, Poland, 211-219
The paper presents the recognition of images using the diffraction pattern sampling. This method, based on properties of Fourier transform, utilizes special shapes of sampling element and gives the possibility to deal with data invariant with respect to typical transformation of the input images. Furthermore, if computer -generated hologram is used as feature extractor, instead of commercially available ring-wedge detector, then the process of feature extraction can be optimized with, proposed by authors, method. The features obtained from diffraction pattern are the input data for the classifier. Since noise involved in images has typically Gaussian distribution, therefore the classification should be made in model with statistical uncertainty. For this purpose artificial neural network is used. The presented method is illustrated with experiments of speckle pattern recognition. -
L.R. Jaroszewicz, Z. Krajewski, R. ¦wiłło, "Application of fiber-optic Sagnac interferometr for
detection of rotational seismic events", Molecular and Quantum Acoustics, 22, (2001), 133-144
A new area of fiber-optic Sagnac interferometer application is presented and discussed. The fiber-optic sensor described in the paper, in well-known classic FOG configuration, has been designed for a detection of the rotational seismic events. The basic system optimisation for a detection rotation only without conversion for angular changes distinguishes this system from the gyro application. On the other side, the detection of absolute rotation can give an advantage for this system in compare to other rotational seismometers, which calculate rotational events in indirect ways. The comparison of data from the described fiber-optic rotation seismometer and two antiparallel pendulum seismometers are also presented. -
L.R. Jaroszewicz, Z. Krajewski, "Optical fibre interferometric system for Doppler effect
measurement", Opto-Electron. Rev., 10, 3, (2002), 185-191
A novel idea of optical fibre laser Doppler velocimetry useful especially for non-contact testing of rotation elements is presented. The main idea of presented system is based on application interferometric measurement of Doppler effect by specially constructed optical fibre interferometer. The standard single-mode coupler, connected with laser diode operated at 0.68 x 10-6 m, has been used as main optical elements. The suitable selection of a target distance from the special constructed optical head secured system work as one-reflection Fabry-Perot fibre interferometer. Such device protected polarisation stability as well as good environmental shielding. The special numeric processing of interferometric output signals by technique based on FFT gives a possibility of rotation element testing. The theoretical investigation was compared with experimental data obtained for the commercially available magnetic hard disc and the dynamically tuned electromechanical gyro. -
L.R. Jaroszewicz, P. Marć, "Measurement of full polarisation parameters using in-line fiber-optic
polarimetric device", Opto-Electron. Rev., 10, 3, (2002), 199-207
The in-line fibre-optic polarisation analyzer enabling measurement of full polarisation parameters of light propagated in optical fibre is presented in the paper. This device uses a standard single-mode optical fibre in a system of the polarimetric configuration. Introduction of controlled birefringence in such a fibre and an application of an appropriate polarizer set at the end of the system allow to get full information about polarisation parameters to obtain. Evaluation of any changes of the state as well as the degree of polarisation have been achieved by application of an appropriate detection system and numerical calculation based on the coherence matrix theory. Finally, some experimental results of system performance and determination of the main errors are presented. -
L.R. Jaroszewicz, P. Marć, "In-line fiber-optic polarization analyzers for sensor application", IEEE
Sensors Journal, 3, 1, (2003),71-79
Theoretical and experimental investigations of a new type of the in-line fiber-optic polarization analyzers are described in the paper. The discussed devices are based on a polarimeter as well as a Sagnac interferometer configuration and give the possibility to detect the full polarization changes. Detection of the polarization state as well as its degree in real time by the systems containing a standard single-mode fiber and application of appropriate modulation technique is a new property of the arrangement. The comparison of the described systems based on experimental devices investigation is also presented in the paper. -
L.R. Jaroszewicz, P. Marć, "Fiber-optic interferometric polarization analyzer", 19th IEEE
Instrumentation and Measurement Technology Conference IMTC2002, 21-23.05.2002, Anchorage, USA, 1497-1502
In the paper theoretical and experimental investigations of a possibility the full polarization parameters measurement by the in-line fiber-optic interferometer in the Sagnac configuration is described. The presented device uses interferometric measurement technique based on the fourth Fresnel-Arago's condition, which secures very good system accuracy and stability. The detection of the polarization state as well as degree of the polarization in real time by the devices containing standard single-mode fiber and an appropriate applied modulation technique is a new system property.
Keywords: fiber-optic sensor, interferometry, polarization measuement -
L.R. Jaroszewicz, P. Marć, "Measurement of polarisation parameters by in-line fibre-optic devices", SPIE,
4900, (2002), 451-458
In the paper theoretical and experimental investigations of a possibility the full polarization parameters measurement by the in-line fiber-optic devices are described. The discussed systems based on the polarimeter as well as Sagnac interferometer configuration. The detection of the polarisation state as well as degree of the polarisation in real time by the devices containing standard single-mode fiber and an appropriate applied modulation technique is a new systems property. The comparison of described systems, based on experimental results, is also presented in the paper. -
L.R Jaroszewicz, Z. Krajewski, "Possibility of fibre-optic rotational seismometer design", SPIE, 4900,
(2002), 416-423 - invited
A new area of fiber-optic Sagnac interferometer application is presented and discussed. The fiber-optic sensor described in the paper, in well-known classic fiber-optic gyro configuration, has been designed for a detection of the rotational seismic events. The basic system optimisation for a detection rotation only without conversion for angular changes distinguishes this system from the gyro application. On the other side, the detection of absolute rotation can give an advantage for this system in compare to other rotational seismometers, which calculate rotational events in indirect ways. The comparison of data from the described fiber-optic rotation seismometer and two antiparallel pendulum seismometers are also presented. -
A.Walczak, E. Nowinowski-Kruszelnicki, L.R. Jaroszewicz, "In-line liquid crystalline polarization
transformer", 19th IEEE Instrumentation and Measurement Technology Conference IMTC2002, 21-23.05.2002, Anchorage, USA, 981-983
A new in-line type tunable liquid crystalline fiber-optic polarization transformer is presented. The main idea is to obtain anisotropic waveguide structure based on biconically tapered isotropic fiber core and anisotropic liquid fiber clad. As the liquid-crystalline clad, the nematic mixture W-602 made by Dąbrowski's group has been used. The special construction of a device with simple external cross-section secures a possibility to change molecular orientation of the liquid-crystalline clad by external field. Thus, different polarizing action has been obtained depending on fulfillment waveguide condition of the structure. -
A. Walczak, E. Nowinowski-Kruszelnicki, L.R. Jaroszewicz, P. Marciniak, "Tuned Fabry-Perot
interferometer", SPIE, 4900, (2002), 901-907
The way for designing and analysis of the tuned Fabry-Perot Interferometer (FPI) for monochromatic wave filtering has been established and presented. The filter is filled with liquid crystal for achieving the tuneable optical axis orientation. The meaning of the refractive index dispersion on the designing and spectral characteristics of the tuned FPI has been explained in detail. The phase of reflection for the electromagnetic waves in the mirroring layers of the filter has been experimentally determined. It allows one to obtain real effective optical thickness of the filter and successfully applied 4x4-matrix method for transmission calculations. The conditions for lc substance parameters to design the FPI filter have been verified. -
A. Walczak, E. Nowinowski-Kruszelnicki, P. Marciniak, L.R. Jaroszewicz, "Multiresolution signal
processing in liquid crystals devices", SPIE, 4759, (2002), 432-437
The particular family of liquid crystalline filters is presented. Their basis application is multiresolution image analysis (wavelet transform). That filter creates polarized beam of light, which constitutes the Haar wavelet. Simulation of such a filter by means of 4x4 matrix as well as xperimental results is also presented. -
A. Walczak, E.Nowinowski-Kruszelnicki, L.R.Jaroszewicz, P.Marciniak, "Tuned liquid crystalline
interferometer analysis by means of generalized Berreman matrix", Opto-Electron. Rev. 10, (2002), 69-73
The analysis of the tuned, liquid crystalline Fabry-Perot interferometer (FPTI) has been done by means of 4x4 matrix. Wide-engle incidence has been analysed in terms of Trollinger-Chipman correction for extraordinary wave. Results have been applied to determine constraints in design of the monochromatic tuned FPTI. Main features of the FPTI device and liquid crystal determining FTPI parameters has been described in detail. Special attention has been paid to dispersion of the LC' refraction indices as a factor of spectral FTPI' properties. -
K.A. Cyran, L.R. Jaroszewicz, U. Stańczyk, "Subsurface stress monitoring system based on holographic
ring?wedge detector and neural network" QRM-2002 - 4th International Conf. Quality, Reliability and Maintenance, Professional
Engineering Publishing Ltd., London, (2002), 65-69
Composite materials are used widely in the areas of industrial production including constructions of carrying elements of airplanes. It gives the possibility to fuse optical fibers into such elements and obtain images of intermodal interference. Since the conditions of interference differ when some kind of subsurface stress is present in composite material, therefore such system can be used for nondestructive monitoring of it. The article presents pattern recognition system that uses genetically optimized holographic ring-wedge detector (HRWD) together with artificial neural network (ANN) and is able to recognize images taken from the optical fiber output. -
L.R. Jaroszewicz, T. Podeszwa, K.A. Cyran, I. Merta, "Airplane engine condition monitoring system
based on artificial neural network" QRM-2002 - 4th International Conf. Quality, Reliability and Maintenance, Professional
Engineering Publishing Ltd., London, (2002), 179-181
The experimental results of the work on a new system for automatic examination of an engine condition are presented in the paper. The main idea of presented system bases on classification of the samples of lubricating oil containing rub products. An application of a fiberscope with the CCD camera and suitable software gives a possibility to obtain filed-working system for quick examination of the engine or wear condition. It can be used during daily service where fast but not very accurate engine condition estimation is enough. -
K.A. Cyran, L. R. Jaroszewicz, T. Niedziela, I. Merta, "Concurrent signal processing in optimized
hybrid CGH-ANN systems", Opt. Appl., 31, (2001), 675-689
The paper presents concurrent hybrid pattern recognition system. The feature extractor of the system is based on optical properties of ring-wedge detector (RWD) or computer generated hologram (CGH) which serves as RWD. The classifier is made as artificial neural network (ANN). Since the feature extraction is an optical and thus fully concurrent process, hence such systems can be designed for real time pattern recognition if only the classifier of characteristic features works fast enough. In presented system the optimized by author's original method CGH is used instead of widely described standard one. The comparison of recognition results for both types of feature extractors is also supplied. In the end the methodology of obtaining fully concurrent system with optimized CGH and optical ANN playing the role of classifier is proposed. -
L.R. Jaroszewicz, P. Marć, "Fiber-optic interferometric polarization analyzer: new approach to
polarization analysis", IEEE Trans. on Instrum. and Meas., 53, 2, (2004), 259-265
This paper presents a new approach to description of the partial polarization in a fiber-optic system. The introduced model is treating depolarization as a distribution of different states of polarization (SOP). The parameters of such SOP distribution function are connected with spectral character of a light source, which may give a depolarization process different from a linear one in an optical fiber system. Such description of light propagation in an optical fiber can be useful for investigation of the polarization mode dispersion. This paper also presents results of the degree of polarization measurement by application of the introduced approach in the fiber-optic interferometric polarization analyzer. This is the fiber-optic Sagnac interferometer which uses a measurement technique based on the fourth Fresnel-Arago's condition of polarized beams interference. -
L.R. Jaroszewicz, A. Zajac, P. Marć, Z. Krajewski, R. ¦wiłło, "Investigation of the polarization
evolution in fiber-optic loop (Sagnac) interferometer", 6th Intern. Conf. on Engineering Design and Automation,
Mauii USA, 4-7.08.2002, Proc. on CD (2002), 98-103
The usefulness of the visualization and animation of polarization influence on a fiber-optic loop interferometer in different engineering applications work is presented. The Jones' matrix calculus has been used for a description as fiber-optic elements as all interferometric systems. Such uniform description gives a possibility to obtain analytical relations, which depend on fundamental system parameters. Unfortunately, these relations are usually too complicated for physical interpretation. From this reason the possibility of such analyze by application of the animated graphics is main subject of this paper. -
A. Zajac, L.R. Jaroszewicz, J. Kasprzak, M. Skórczakowski, P. Marć, Z. Krajewski, "Diagnostics of
biological tissues by the fiber-optic interferometric system with Cr:Forsterite laser pumped by Nd doped fiber-laser",
6th Intern. Conf. on Engineering Design and Automation, Mauii USA, 4-7.08.2002, Proc. on CD (2002), 112-117
The possibility of using short-pulse laser with interferometric fiber-optic system for diagnostic of biological tissues is presented. The picosecond pulses Cr:Forsterite laser pumped by Nd doped fiber-laser, operated at 1300 nm is proposed and the first characteristics of such laser are presented. The detection of backscattering light from biological tissues is obtained by application of the Michelson type fiber-optic interferometer. The main aspect of signal processing based on a phase calculation as well as theoretical system description in the Jones' matrix approach is presented in the paper, also. -
K. Stasiewicz, L. R. Jaroszewicz, "Automatic set-up for advanced optical fiber elements
manufacturing", SPIE, 5952, (2005), 233-239
This paper describes a special set-up which principle of operation bases on elongation procedure of fiber-optics in a low-pressure gas burner. The universal construction of set-up makes it possible to prepare different elements from any kind of optical fibers, including single-mode, multi-mode and polarization maintaining as well as optical fiber with different indices distribution and operation wavelengths. The basic element is fiber-optic biconical taper (diameter about several um on length up to 10 -15 mm), which due to a small cross-section enables achievement of optical beam propagation outside the fiber in direct way. The paper presents the overview of different elements, which structure is based on above taper, such as: X-type in-line fiber-optic couplers operating in a wide range of wavelengths, in-line optical polarizers as well as polarization switchers. An important thing about these elements is a possibility to operate in the wavelength different from the classical telecommunication range. -
A. Walczak, E. Nowinowski-Kruszelnicki, L.R. Jaroszewicz, R. Wal, "Edge detection with liquid crystal
polarizing filter" Mol. Cryst. and Liq. Crystal., 413, (2004), 407-415
The liquid crystalline filter exhibiting particular optical properties is presented. Their basis application is multiresolution image analyzer based on wavelet transform (WT). In co-operation with the phase shifter such filter allows to rotate the polarization of the transmitted light. The resulted intensity distribution is a tool to span the transmitted picture onto the space of circular Haar wavelets. Those phenomena provide new possibilities in optical signal processing. The analysis of transmission in considered filter as well as wavelet space creation is described, also. -
A. Walczak, E. Nowinowski-Kruszelnicki, L.R. Jaroszewicz, P. Marciniak, "Design of the
tuned transmission in Fabry-Perot filter", ABTOMETRIA Optoelectronics, Instrum. and Data Processing, 39, 5,
(2003), 69-76
The way for design and analysis of the tuned Fabry-Perot Filter (FPF) for a monochromatic wave filtering has been established and presented. The filter is filled with liquid crystal (LC) to achieve controlled variation of the optical axis. The dependence of the spectral characteristics of the tuned FPF on the refractive index dispersion has been explained in detail. The phase of reflection for the electromagnetic waves in the reflecting layers inside the filter has been experimentally determined and included into the FPF analysis. The way for the extinction determination in transparent, scattering LC layer has been shown as well. -
T. Podeszwa, L.R. Jaroszewicz, K. Cyran, "Fiberscope based engine condition monitoring system",
SPIE, 5124, (2002), 299-303
The article presents the engine condition monitoring system. The system uses dependence between amount of rub products gathered in lubricating oil and current wear condition of device. The measure method bases on ferrographic method. Images are taken from sample and magnified by fiberscope, and then converted by CCD camera into digital form. Then raster images are classified by dedicated computer system. This paper presents actual state of system research. -
K. A. Cyran, T. Niedziela, L.R. Jaroszewicz, T. Podeszwa, "Neural classifiers in diffraction
image processing", International Conference on Computer Vision and Graphics ICCVG-2002, 25-29.09.2002, Zakopane,
Poland, 223-228
The paper presents the application of PNN and MLP neural networks into hybrid opto-electronic image recognition system, based on Fraunhofer diffraction pattern sampling. The mentioned diffraction patterns of input images can be either obtained with the use of optical signal processing techniques or by discrete Fourier transform. In both cases NN can be applied to classify feature vectors obtained by sampling the diffraction pattern and integrating its intensity over rings and wedges. The comparison and short discussion of the accuracy of these two types of neural networks applied to classification on Fraunhofer diffraction images is also included in a paper. -
L.R. Jaroszewicz, Z. Krajewski, L. Solarz, R. Teisseyre, "Fiber-optic Sagnac interferometer
as a system for the electromechanical rotational seismometer calibration and a new senor of the rotational seismic
events", EGS-AGu-EUG Joint Assembly, 7-11.04.2003, Nice, France, see my www page - projects 13
The possibility of the fiber-optic Sagnac interferometer application as a system for absolute rotation events detection is discussed and presented. The basic system optimization for only rotation detection without its conversion for angular changes distinguishes this system, named further Fiber-Optic Rotational Seismometer (FORS) from the gyro applications. The main advantage of the system is a possibility to measure of the absolute rotation rate around any axis perpendicular to the optical path plane, not being sensitive to a uniform linear motion or distortion. This feature of the FORS seems to be advantageous in comparison to other rotational seismometers, which calculate rotational events in indirect ways. The example of the latter is the electromechanical rotational seismometer - TAPS. Unfortunately, this system is characterized by extremely high sensitivity to translation motions, and can have limited precision of rotational wave detection. Moreover, there exists a serious problem with good calibration.From this reason the designed portable system FORS-I with sensitivity 6xE-6 rad/s has been used for investigation of the proper action of TAPS as well as confirmation of the existing rotational events during the same earthquake. In this area a new method of TAPS calibration based on data smoothing by spline functions are presented. -
L. Solarz, Z. Krajewski, L.R. Jaroszewicz, "Analysis of seismic rotations detected by two
antiparallel seismometers: Spline function approximation of rotation and displacement velocities", Acta Geophys. Pol.,
53, 2 (2004), 198-217
The task of getting more reliable results of seismic rotation measurements has been undertaken in the paper. The rotation is caused by seismic events and measured by a system of two antiparallel pendulum seismometers (TAPS). Theoretical analysis of TAPS system is presented taking into account that seismometers are not identical. Such approach, due to modelling of electro-mechanical phenomena in the seismometers and smoothing of the registered measurements by spline approximation method, gives better reliability of the measurements analysis. -
L.R. Jaroszewicz, Z. Krajewski, L. Solarz, P. Marć, T. Kostrzyński, "A new area of the fiber-optic
Sagnac interferometer application”, Intern. Microwave and Optoelectronics Conference IMOC-2003, 20-23.09.2003 Iguazu
Falls, Brasil, 661-666
In the paper a new areas of the fiber-optic Sagnac interferometer applications are discussed. The presented devices basing on well-known optical gyroscope configuration are optimized for detection of other special physical quantities. Generally it is a rotational seismometer designed for calibration of the other electromechanical types of such devices, as well as a new sensor for detection of rotational seismic events. The detection of absolute rotation by the system is advantageous in comparison to the other rotational seismometers, which calculate rotational events in indirect ways. The paper describes comparison of the data obtained from the fiber-optic rotational seismometer and the electromechanical one. Additionally, the application of the fiber-optic loop interferometer basing on Sagnac configuration for investigation of stability of polarization parameters of light used in the fiber-optic rotational seismometer is also discussed. -
P. Marć, L. R. Jaroszewicz, "Distribution function approach to degree of polarization phenomenon
description in optical fiber system", SPIE, 5158, (2003), 54-62
The paper presents a new approach to description of the partial polarization in a fiber-optic system. Basing on the investigation of interference phenomenon in a fiber-optic Sagnac interferometer the depolarization process is defined applying statistical point of view. The introduced model is treating depolarization as a some distribution of different states of polarization (SOP). The parameters of such a SOP distribution function are connected with spectral character of a light source, which may give depolarization process different from a linear one in an optical fiber system. Such description of light propagation in an optical fiber can be useful for investigation of the polarization mode dispersion. This paper presents also results of the degree of polarization measurement by application of the introduced approach in the fiber-optic interferometric polarization analyzer. This is the fiber-optic Sagnac interferometer which uses a measurement technique based on the fourth Fresnel-Arago’s condition of polarized beams interference. -
A.S. Zajac, L.R. Jaroszewicz, M. Skórczakowski, P. Marć, "OCT system with fiber-optic
interferometr and Cr:forsterite laser", SPIE, 5140, (2003), 221-228
The possibility of using short-pulse laser with interferometric fiber-optic system for diagnostic of biological tissues is presented. The picosecond pulses Cr:Forsterite laser pumped by Nd doped fiber-laser, operated at 1300 nm is proposed and the first characteristics of such laser are presented. The detection of backscattering light from biological tissues is obtained by application of the Michelson type fiber-optic interferometer. The main aspect of signal processing based on a phase calculation as well as theoretical system description in the Jones' matrix approach is presented in the paper, also. -
L. R. Jaroszewicz, Z. Krajewski, L. Solarz, "Usefulness of the fiber-optic interferometer
for detection of the seismic rotation waves", ABTOMETRIA Optoelectronics, Instrum. and Data Processing, 39, 5,
(2003), 91-101
In the paper a new application areas of the fiber-optic interferometer in the Sagnac configuration are discussed and proposed. Because this system detects the absolute rotation in a plane of its sensor loop, the application is directly designed for detection of the rotational events. Form seismological point of view such events can exist as rotational parts in the seismic waves and are named seismic rotation waves. In most cases the seismic rotation waves are extracted from recordings of differential seismic signals. Thus, all differences in responses of the seismometers cause disturbances which obscure these hidden components as it is for two antiparallel pendulum seismometers (TAPS) system. The presented device, named fiber-optic rotational seismometer (FORS), is free from this disadvantage, and may be used for other rotational seismometer calibration as well as for a direct seismic rotation waves detection. The paper describes the design based on well-known optical gyroscope configuration but with optimization for detection only the pure rotation as well as its application for the TAPS system calibration. The obtained results have been the source of TAPS work improvement by applying the data smoothing by spline function. Moreover, the first application of FORS has shown that probably rotational parts exist in the seismic events only for the strong earthquake. -
K. Fedak, I. Merta, L.R. Jaroszewicz, "Fundamental properties of the selected joint transform
correlators for practical application in automatic images recognition", SPIE, 5484, (2003), 452-459
The paper presents review of the selected joined transform correlators (JTC) used for automatic images recognition. Because they are used in non-contact optical measurement systems thus special numerical processing should be used for analysis of data collected by them. The neutral network approach, wide development in last decade for such system, seems to be small useful, mainly because it creates computing model. The image is parallel information and such method as the Fourier transform are more useful for its processing. From this reason the wavelet transform as generalization of the Fourier method has been chosen as optimal. On this base the JTC uses wavelet transforms (WT) for analysis because it is a powerful tool for wavelet filtration, image feature extraction and recognition of rationally distorted images. The laboratory system uses the joint wavelet transform correlator (JWTC) and its possibilities were presented on this paper as final result of review. -
P. Marć, L. R. Jaroszewicz, "Distribution function approach to degree of polarization phenomenon
description in optical fiber system", SPIE, 5158, (2003), 54-62
The paper presents a new approach to description of the partial polarization in a fiber-optic system. Basing on the investigation of interference phenomenon in a fiber-optic Sagnac interferometer the depolarization process is defined applying statistical point of view. The introduced model is treating depolarization as a some distribution of different states of polarization (SOP). The parameters of such a SOP distribution function are connected with spectral character of a light source, which may give depolarization process different from a linear one in an optical fiber system. Such description of light propagation in an optical fiber can be useful for investigation of the polarization mode dispersion. This paper presents also results of the degree of polarization measurement by application of the introduced approach in the fiber-optic interferometric polarization analyzer. This is the fiber-optic Sagnac interferometer which uses a measurement technique based on the fourth Fresnel-Arago’s condition of polarized beams interference. -
Z. Krajewski, L.R. Jaroszewicz, "FORS-II as a optimum sensor for detection of the rotational
seismic events", SPIE, 5484, (2003), 406-409
Generally, the seismic waves appear during the earthquake are bulk longitudinal or transverse type waves. However, the last developed theory shown that so called seismic rotation waves exist, also. These waves appear in the case of non-ideal elasticity due to defect content in a medium or due to internal structure of the medium. The detection such kind of waves should use new techniques because conventional seismographs are inertial sensors for linear acceleration, only. Form this reason the Fiber-Optic Rotational Seismometer (FORS) based on the fiber-optic Sagnac interferometer is proposed. The main advantage of such system is measurement of absolute rotation around any axis perpendicular to the optical path plane and without sensitivity to uniform linear motion or distortion. In the article system FORS-II currently developing is presented. This system using appropriate system configuration has extremely high sensitivity without characteristic for the fiber-optic gyro sensitive on polarisation phenomenon -
P. Marć, L.R. Jaroszewicz, T. Kostrzyński, "Estimation of the indication error in the fiber-optic
polarisation analyzers", SPIE, 5484, (2003), 410-416
The main technical parameters characterize work of optical fiber sensors for detection in real time polarisation parameters of light are investigated in this paper. Generally, parameter defined as precision is used for comparison two in-line fiber-optic polarisation analyzers where one used polarimetric and second interferometric sensor configuration. The theoretical description of those systems uses the coherence matrix and the Jones matrix calculus approach for partially polarised light source and fiber-optic elements, respectively. Such theoretical analyse permits obtaining analytical relations for polarisation parameters based on measuring of electrical quantities. These relations were principle for describing theoretical measurement error. The experimental results obtained from testing of laboratory analyzer models had been used for definition of fundamental system parameter named system device precision, which uses statistical model. Results of these analyses showed that inteferometric system allows more precise determination of the state of polarisation in shorter measurement time. The polarimetric system gave worst precision what was caused mainly by temperature instabilities during adjusting procedure. However precision of both systems are better then in a bulk-optic analyzers. -
P. Marć, L.R. Jaroszewicz, "Automatic in-line fiber-optic polarization analyzers", SPIE, 5459,
(2004), 319-327
TIn the paper two different configurations of automatic in-line fiber-optic polarization analyzers are presented. The principle of operation is based on birefringence modulation in the standard single-mode fiber and suitable detection of the harmonic amplitudes of the output electric signals. In the first one, called Fiber-Optic Polarization Analyzer, the polarimetric configuration with polarization modulation by squeezing a single-mode fiber is used. In the second, called Fiber-Optic Interferometric Polarization Analyzer, the modified Sagnac interferometer with standard piezoceramic ring modulator is applied. For both configurations briefly theoretical analysis of the polarization phenomenon is presented. As a main part of the paper the experimental results of the state as well as the degree of polarization parameters measurement are shown. In the experimental systems digital oscilloscope, function generator and PC with HPiB card and HP-VEE software for identification polarization parameters are used. In conclusion both systems are compared - especially form measurement time and errors points of view. -
L. R. Jaroszewicz, Z. Krajewski, L. Solarz, "The fiber-optic Sagnac interferometer application
for recognition of the rotational seismic events", SPIE, 5459, (2004), 272-280
In the paper a new areas of the fiber-optic Sagnac interferometer applications are discussed. The presented devices basing on well-known optical gyroscope configuration are optimized for detection of other special physical quantities. Generally it is a rotational seismometer designed for calibration of the other electromechanical types of such devices, as well as a new sensor for detection of rotational seismic events. The detection of absolute rotation by the system is advantageous in comparison to the other rotational seismometers, which calculate rotational events in indirect ways. The paper describes comparison of the data obtained from the fiber-optic rotational seismometer and the electromechanical one. Moreover, on this base the construction of new system with resolution 10 E-8 rad/s is also presented in this paper. -
L.R. Jaroszewicz, Z. Krajewski, P. Marć, "Fiber-optic Sagnac interferometer as a sensor of physical
quantities", SPIE, 5502, (2004), 390-393
The fibre-optic Sagnac interferometer as an example of the point sensor is described in this paper. The described applications comprising a system for rotational tables' investigation, a system for measurement of vibrations with an amplitude of nanometre order of magnitude, devices for polarisation parameters analysis and the rotational waves detector base on reciprocal condition of the Sagnac interferometer operation. Because the coherence phenomenon in this configuration occurs in any source of light, the polarisation role in this configuration is emphasized. Basing on this approach the possibilities of practical use of the polarisation influence on interference phenomenon for the mentioned above devices are mainly discussed. -
L. R. Jaroszewicz, "Polarization role in fiber-optic interferometry", SPIE, 5531, (2004), 170-180
Because the single-mode optical fiber keeps spatial coherence in fiber cross-section and the selected interferometric configuration also the temporal one, the coherence aspect in optical-fiber interference phenomenon can be omitted. Basing on this fact and taking into consideration the anisotropic properties of optical fiber, the fiber-optic interferometer gives a possibility for direct analysis of polarization role in the interference phenomenon as well as possibilities of their practical use. Such idea is presented in this paper where the theoretical as well as experimental investigation base on fiber-optic loop interferometer configuration is presented. The practical aspect of this analysis is developed in the systems described in this paper and designed for: slow-speed platform investigation, detection of rotational seismic waves, fiber-optic element investigation, and polarization parameters analysis. -
L. R. Jaroszewicz, Z. Krajewski, L. Solarz, "Fiber-optic Sagnac interferometer as a sensor of the seismic
rotation waves", SPIE, 5855, (2005), 194-197
The paper presents new results connected with the fibre-optic Sagnac interferometer (FORS-II) application for seismic rotation waves (SRW) investigation. Generally it is a fibre-optic rotational seismometer based on its resolution in the range of 4.27xE-8 rad/s which can detect the SRW in the direct way. The paper presents the analyses of the experimental results obtained in Ojców standard seismic observatory. The discussion presented in the paper shows a new aspect connected with physical fundamentals of the seismic rotation waves. -
L. R. Jaroszewicz, Z. Krajewski, L. Solarz, R. Teisseyer, "Application of the FORS-II for investigation
of the seismic rotation waves', SPIE, 5776, (2005), 385-393
In the paper new results connected with application of the fiber-optic Sagnac interferometer in the area of investigation of special seismic events are discussed. The device presented in the paper is designed for investigation of rotational component existing in the earthquakes called seismic rotation waves. Generally it is a fiber-optic rotational seismometer (FORS) based on its resolution in the range of 10xE-8 rad/s which can detect the seismic rotation waves in a direct way. The paper describes the first results obtained on the base of data recorded in Ojców standard seismic observatory. The presented discussion in paper shows a new aspect connected with physical fundamentals of the seismic rotation waves. -
P. Marć, L. R. Jaroszewicz, "Uncertainties of the polarization parameters measurement in the fiber-optic
devices", SPIE, 5776, (2005), 377-384
In the paper details of analysis measurement uncertainties of the polarization parameters in the in-line fiber optic devices were presented. For measurement of polarization parameters two fiber optic devices were used. The firs one Fiber-Optic Polarization Analyzer (FOPA) and the second one Fiber-Optic Interferometric Polarization Analyzer (FOIPA). The main idea of both devices operation is comparable and consists in measurement of appropriate electric signals by using polarization sensitive detectors and basing on its calculate polarization parameters. Uncertainties of measurement these parameters were considered from standard low of propagation uncertainties point of view. The experimental results obtained from testing of laboratory analyzers allow estimating standard deviations (uncertainties) and covariances measured electric quantities. Based on these information the theoretical model of uncertainties of the polarization parameters on its ranges were proposed. Results of these analyses showed that inteferometric device allows more accurate and in shorter measurement time. The polarimetric devices gives worst accuracy what was caused mainly by temperature instabilities. However measurement uncertainties of polarization parameters of both systems are better then in bulk-optic analyzers. -
L. R. Jaroszewicz, Z. Krajewski, S. Solarz, R. Teisseyre, "Usefulness of the fiber-optic interferometer for
investigation the seismic rotation waves", Opt. Appl., 35, 2 (2005), 383-394
In the paper a new areas of the fiber-optic Sagnac interferometer applications are discussed and proposed. Because this system detects the absolute rotation, its application is directly designed for detection of the seismic rotation waves which are rotational events existing in the seismic waves. In most cases those waves are extracted from recordings of differential seismic signals. However, all differences in responses of the seismometers cause disturbances which obscure these hidden components as it is for two antiparallel pendulum seismometers (TAPS) system. The presented device, named fiber-optic rotational seismometer (FORS), is free from this disadvantage and may be used for other rotational seismometer calibration as well as for a direct seismic rotation waves detection. The paper describes the design based on well-known optical gyroscope configuration but with optimization for detection only the pure rotation as well as its application for the TAPS system calibration. The obtained results have been the source of TAPS work improvement by applying the data smoothing by a spline function. Moreover, the first application of FORS for recording rotational parts existing in the seismic events has shown that they probably propagate with different velocity than classical earthquake waves. -
I. Merta, L. R. Jaroszewicz, S. Swiłło, "Simple method of the 3-D shape measurement by system of
fibre-optic fringe projection", SPIE, 5952, (2005), 461-470
A shape measurement method combining the fibre-optic interferometric fringe projection method and effective numerical spatial phase unwrapping method is proposed in this paper. Simplicity of the system arrangement determining low set-up cost is the main advantage of the presented approach. The paper presents a detailed theoretical method description. It is based on a specially worked out procedure of an automated analysis of the fringe patterns obtained by the Fourier transform and phase unwrapping based on the Mathematica software procedures. Experimental results of the measurements made for a real object show usefulness and efficiency of the proposed method. -
Z. Krajewski, L. R. Jaroszewicz, L. Solarz, "Optimization of fiber-optic Sagnac interferometer for
detection of rotational seismic events", SPIE, 5952, (2005), 240-246
The optimization of fiber-optic Sagnac interferometer as a sensor for the investigation of seismic rotational waves is presented in this paper. The main parameter of this optimization is maximum system sensitivity for absolute rotation in the limited range of expected velocities. The main system construction bases on the FOG minimum configuration, however the detection by system only rotational velocity without covering it on angle changes needs other approach to this system. The presented in paper theoretical and experimental investigation shows that such system can be made on base of a standard single-mode optical fiber, however needs operation on depolarized light. -
A. Michałkiewicz, P. Marć, M. Kujawińska L. R. Jaroszewicz, "Digital holographic interferometry system
based on all fiber phase modulation", SPIE, 5952, (2005), 80-88
Digital holographic interferometry (DHI) is a modern technique, which allows direct access to the interference phase in holographic interferometry. In order to implement DHI in commercial application the system has to fulfil several requirements including: automatic data capture, compactness and easiness of usage (often remote), high quality of output data. In order to perform those conditions we propose the fiber optic based DHI system with enhanced quality of holograms and decreased sensitivity to vibrations and environmental changes. These special features are achieved by: fiber optic based light delivery endoscope and possibility to introduce all-fiber phase modulation in one of the E-M beams manipulation, monolithic design of sensor lead, which decrease sensitivity of the system to mechanical vibrations, combined passive and active noise suppression and DH quality enhancement. The design considerations and the results of initial experiments performed at the model of the fiber optic based DHI system are presented and discussed. -
L. R. Jaroszewicz, Z. Krajewski, R. Teisseyer, "Some aspects of seismic rotational waves SRW recognition
by fiber-optic rotational seismometer FORS-II", SPIE, 5952, (2005), 64-71
In this paper we have described new results obtained during investigation of seismic rotational waves simultaneously by TAPS - two antiparallel pendulum seismometers system as well as by FORS-II - fiber-optic rotational seismometer. The main advantage of such approach is a possibility to recognize the velocity of seismic rotational waves which seems to be different from velocities of other seismic waves. The experimental data presented in the paper are confirmed by theoretical description of seismic rotational waves' nature. -
L. R. Jaroszewicz, Z. Krajewski, S. Solarz, R. Teisseyre, "Application of the fibre-optic Sagnac interferometer
in the investigation of seismic rotational waves", Meas. Sci. Technol., 17, 4, (2006), 1186-1193
This paper presents new results connected with the fibre-optic Sagnac interferometer application in the investiga-tion of seismic rotational waves. In general, it is a fibre-optic rotational seismometer representing sensitivity equal to 4.27 E-8 rad/s which can detect seismic rotational waves in a direct way. This paper presents the ex-perimental results obtained simultaneously by a fibre-optic and a standard rotational seismometers installed in the Ojcow seismic observatory. The main advantage of such an approach is the possibility of recognizing the velocity of seismic rotational waves, which is different from the velocities of other seismic waves. The experi-mental data presented in this paper are confirmed by the theoretical description of the nature of seismic rotational waves. -
P. Marc, L. R. Jaroszewicz, "Fibre-Optic Sagnac interferometer as sensor of the SOP changes", SPIE
Photon-ics Europe 3-7.04.2006, Strasbourg, France, SPIE, 6189, (2006), 60-67
The fibre optic Sagnac interferometer (FOSI) has many useful applications begin from gyro up to many kinds of sensors for detection different physical quantities. In this paper a new application of FOSI as the sensor of the state of polarisation (SOP) changes is presented. The optical part of system based on minimum gyro configura-tion but a high level polarizer is replaced to specialized polarisation filter with 3dB extinction ratio. Theoretical description of the system is made with application the standard Jones matrix calculus. The system uses the fibre optic phase modulator for investigation of the SOP changes on the base of detecting appropriate harmonic amplitudes of the output signals. Two "dead end" of the FOSI are used for input intensity control as well as for its stabilisation. This system could be use for easy active stabilisation of the SOP in the fibre optic system where the polarisation fading is main disadvantages. -
A. Michalkiewicz, M. Kujawinska, P. Marc, L. R. Jaroszewicz, "Miniaturized low-cost digital holographic
interferometer", SPIE Photonics Europe 3-7.04.2006, Strasbourg, France, SPIE, 6188, (2006), 41-47
Digital holography (DH) and digital holographic interferometry (DHI) are very useful, robust, full-field visualization and measurement techniques applied for small objects, especially in the field of bioengineering and microelements system testing. Nowadays CCD/CMOS detectors and microlasers allow to build miniaturized and compact digital holographic head. Various approaches to develop DH/DHI systems including a variety of optical and mechanical solutions have been made. The main recent requirements for holocamera design include compactness, insensitivity to vibrations environmental changes and with good quality of output data. Other requirement is the ability to build a low-cost and robust system for sensing applications. In our paper, we propose a design of miniaturized holo-camera head with fibre optics light delivery system and remote data read-out. The opto-mechanical architecture allows out-of-plane and shape measurements of diffuse and reflective surfaces. The possible data capture schemes and software for enhanced quality numerical reconstruction of complex objects are discussed and the optimized methodology is determined. Also real-time optoelectronic hologram reconstruction is demonstrated on the base of remote data delivery to liquid crystal on silicon spatial light modulator. The performance of the system is tested on the resolution amplitude test and master sphere, while engineering objects in the experiments are static and dynamic microelements. -
L. R. Jaroszewicz, Z. Krajewski, L. Solarz, "Absolute rotation measurement based on the Sagnac effect",
in R. Teisseyre, M. Takedo, E. Majewski eds. Earthquake, Source Asymmetry, Structural Media and Rotation Effects, Springer-Verlag,
Berlin 2006, 413-438
This chapter deals with technical aspects of absolute rotation measurement based on the Sagnac effect. Starting from a brief description of this effect, its explanation based on different physical approaches is presented. Overviews of optical gyroscopes as a technical implementation of the Sagnac effect for angular position measurement are shown. Differences between gyro and rotation measurements are pointed out. On this basis, fundamental investigations connected with attainable accuracy of the designed fibre-optic rotational seismometers (FORS) are presented. Sensitivity, resolution, noise and drift phenomena are discussed. Finally, technical implementation of different constructions of FORS are proposed. -
L. R. Jaroszewicz "Fibre-optic Sagnac interferometer as real sensor of the physical quantities", Symp. on Photonics
Technologies for 7th Framework Programme, Wroclaw 12-14.10.2006, 99-102 - invited
The fibre-optic gyro is the best known technical application of the fibre-optic sensor, but from physical point of view it is not the unique possible Sagnac interferometer application. Because configuration of such system protects the same optical ways for two interacting beams hence provides good environmental stability, and can be also useful for construction other sensors of the physical quantities. Hence, the short description of the Fibre-Optic Rotational Seismometer, the Fibre-Optic Interferometric Polarisation Analyzer, and the Fibre-Optic Sagnac Element Investigation System are presented in this paper. -
I. Merta, L. R. Jaroszewicz, "Demodulator of phase signal for single mode fiber-optics", SPIE, 6585, (2007), 6585-88
The basic optical set-up for demodulation of phase signal propagating in singlemode fiber - optics was described in this article. In this arrangement two fiber - optics (modulated signal in first and reference in second) was used. Both fibers in the final part of this set-up are parallel to each other at distance between them equals "d". After propagation by fiber beam goes through the lens. The spatial distribution of light amplitude in the focal plane of the lens is proportional to the Fourier transform on the output light in fibers and modulated with frequency proportional to "1/d". The power spectral density of the spatial distribution of light by bicell photodetector was analyzed. The sum and difference of output signals from channels on the detector is depending on the power spectral density, bicell gap and cosine and sine of phase respectively. On the ground of this results it is possible to identify demodulate of different types of modulation without any a priori information. -
A. Michałkiewicz, M. Kujawińska, K. Stasiewicz, L.R. Jaroszewicz, "Digital holocameras for laboratory and outdoor measurements of engineering objects", SPIE, 6616, (2007), 66162P 1-7
Industrial inspection requires very fast and reliable measurements. One of the techniques, recently widely used for monitoring of engineering objects, is digital holographic interferometry (DHI). In the paper we present novel digital holographic cameras (DHC). Their configuration allows to provide high accuracy information about shape, out-of-plane and in-plane displacement distributions, through capture of digital hologram by CCD, numerical reconstruction of phases and their proper manipulation. Digital holographic systems presented have compact design, fibre optics light delivery system and automatic data acquisition and processing. The cameras capture data in real-time and have low sensitivity to environmental changes. In the paper several examples of engineering application of these cameras are presented. -
K. Stasiewicz, L. R. Jaroszewicz, "Controlling and changing the polarization parameters in an optical fiber taper", SPIE, 6588, (2007), 6588-40
The possibilities of controlling and changing the state of polarization (SOP) as well as the degree of polarization (DOP) in an optical fiber taper are described in this paper. The in-line polarization analyzer POD-101A and Pola ViewTM software have been used for above polarization parameters investigation. In ours analyze we used a few kinds of optical fiber like: singlemode, multimode and photonic crystal ones. All of them were tapered in two different method to obtain different diameter and length of a waist. Diameter of taper waist was changing from 125 um to about 50 um for total taper length up to 100 mm. Polarization parameters was measured for wavelength 1310 nm. Set-up for manufacturing taper and software for measuring polarization also allows to produce optical fiber couplers and measured changes on their outputs. -
K. Stasiewicz, L.R. Jaroszewicz, "Tapered fiber as a base element for obtaining and controlling of a supercontinuum generation", SPIE, 6608, (2007), 66080N 1-7
The obtained result of broadening spectral bandwidth known as "supercontinuum generation" are described in this paper. This effect is usually obtained by transmission a very short laser impulse through a strongly nonlinear element like optical fiber (especially photonic crystal fiber). Supercontinuum generation can be also obtained by propagation short impulse form (nanosecond pulses from Nd:YAG laser at 532nm wavelength with average power 300mW) through tapered conventional optical fiber (COF) or tapered endlessly single mode photonic crystal fiber (PCF). In these paper we are showing our first result of obtaining this effect. -
L. R. Jaroszewicz, R. Swiłło, Z. Krajewski, "Numerical simulation and optimization of the fiber-optic sensors in Sagnac configuration by investigation their polarization properties", SPIE, 6585, (2007), 6585-87
The usefulness of the visualisation and animation of polarisation influence on the fibre-optic sensors in the Sagnac configuration is presented. The Jones' matrix calculus and the coherence matrix approach have been used for the fibre-optic elements and all interferometric systems description, respectively. Such uniform description gives a possibility to obtain analytical relations, which depend on fundamental system parameters. Because the final relations are usually too complicated for physical interpretation, the possibility of simulation of system work by application of the animated graphics is main subject of this paper. -
Z. Krajewski, L.R. Jaroszewicz, "Rotation effects as components of seismic events", SPIE, 6608, (2007), 6608G 1-8
In the paper the concept of optical sensor FORS-II (Fiber-Optic Rotational Seismometer) application for detection of rotation effects occur during seismic events is presented. The main advantage of the FORS-II is its very high sensitivity in the range of about 2.10-8 rad/s. Result of the system research and experimental data comparison with data obtain by two antiparallel pendulum seismometers are also presented. Finally, theoretical concept of observed rotation effects during seismic events is also presented. -
L.R. Jaroszewicz, Z. Krajewski, "Identification near-field seismic rotational events by fibre-optic rotational seismometer", SPIE, 6619, (2007), 66192D-1-4
The paper presents new results about identification near-field seismic rotational events by a fibre-optic rotational seismometer. The Sagnac interferometer with 2 sigma sensitivity equal to 4.27 10-8 rad/s has been used as rotational seismometer, which can detect rotational events in a direct way. The theoretic investigation of obtained results show that such events can be treatment as the seismic rotational waves. The paper presents the experimental results obtained simultaneously by a fibre-optic and a standard rotational seismometers installed in the Ojcow seismic observatory. The main advantage of such an approach is a possibility to recognize the velocity of seismic rotational waves, which is different from the velocities of other seismic waves. -
L.R. Jaroszewicz, Z. Krajewski, "Fiber-Optic Rotational Seismometer as device for detection the seismic rotational events", 24th IEEE Instrumentation and Measurement Technology Conference IMTC/2007, Warsaw (2007), We1ef- 7660-1-5
The fibre-optic Sagnac interferometer application for a direct measurement of ground rotation component is presented in this paper. It is a new rotational seismometer which parameters are compared with classical mechanical one. On this base the experimental data obtained during simultaneously application above two kinds of sensors are also presented. It is directly shown that rotational components, so-called rotational seismic waves, exist in separation to classical seismic waves generated during earthquakes. -
R. Swiłło, L.R. Jaroszewicz, "The compact and stabile operating fibre optical coherence tomography for medical application", SPIE, 6619, (2007), 66194D-1-4
A new idea of the fibre optical coherence tomography designed for medical application is presented in this paper. The system can be used for canning the interior of human body thanks to application of special optical head based on single-mode fibrescope. The special construction of the fibre-optic Michelson interferometer with the pulse-doubling system protects high temperature and polarisation system stability, whereas compact construction of the optical head gives usefulness for practical application. The optical fibre output port can also be easy attached to conventional miniature CCD camera. In this way the two dimensional image generated by camera will be upgraded with longitudinal cross-section of observed structure . -
L. R. Jaroszewicz, Z. Krajewski, "Application of the fibre-optic rotational seismometer in investigation of the seismic rotational waves", Opto-Electron. Rev., 16, 3, (2008), 314-320
Application of the fibre-optic Sagnac interferometer as a rotational seismometer is presented in this paper. It is a new device which parameters (sensitivity equal to 4.3 10-8 rad/s for 2 sigma) are comparable with the parameters of classical mechanical rotational seismometers. However the direct measurement of rotation without influence of the linear motions for fibre-optic rotational seismometer designed it for a direct measurement of ground rotation component. Therefore the experimental data obtained during a simultaneous application of the above two types of sensors are also presented. Research of the near-field seismic events which amplitude have been identified in the range of 1.5 10-6 rad/s to 2 10-7 rad/s shows directly that so-called seismic rotational waves exist independently of the classical seismic waves generated during earthquakes. -
R. Swiłło, L.R. Jaroszewicz, B. Pura, "New Optical fibre coherence tomography - compact and stabile system for medical application", IEEE Sensor Journal, 8, 7, (2008), 1138-1144
A new idea of the optical fibre coherence tomography system designed for medical application is presented in this paper. Application as a source the femtosecond 400 mW Ti:Al2O3 pulse laser operates at wavelength 798 nm with spectral pulse bandwidth about 145 nm provides the longitudinal resolution about 2 um. The system can be used for scanning the interior of a human body owning to application of a special optical head based on single-mode fibrescope. The structure comprises a set of two fibre-optic interferometers. The first of them is a Michelson type which enables the doubled pulses generation with spatial separation directly correlated with a deep scanning in the investigated sample. The second one is partially delayed Fizeau interferometer formed on the end of optical fibre providing a high temperature and polarisation system stability. The discussed set-up consists also of a new signal processing structure based on synchronous detection scheme and application of the lock-in amplifier allowing investigation of the reflection coefficient of investigated sample via a suitable numerical processing of the first two harmonic amplitudes of the detected signals. The experimental results of OCT reconstruction of a tree leaf in area 150 x 1750 um giving a possibility to recognize various kind of tissues are also presented. -
L. R. Jaroszewicz, J. Wiszniowski, "Measurement of short-period weak rotation signals", in R. Teisseyre, H. Naagahama, E. Majewski (Eds): Physics of Asymmetric Continuum: Extreme and Fracture Processes, Springer-Verlag, Berlin 2008, 17-48
The chapter presents the review of methods for short period low rotation signals measurement. It is shown necessary for new instrumentation which principle of operation eliminates sensitivity for linear motion. Moreover, it is shown that used seismometers have to special care of positioning, selecting examples with the same response, and calibration. They should be rather used as an array, that compromise the resolution and frequency of rotation signals. The practical expected sensitivity less than nrad/s preferred system operates on the base of the optical Sagnac effect such as laser or fibre-optic systems or magnetohydrodynamic sensors. The results obtained on this ground in Ojcow Observatory prove that the real seismic rotational events are delayed in time with regard to the classical seismic wave existing during earthquakes. Moreover, the recorded amplitude of these events, connected with the quarry situated near to fibre-optic rotational seismometer localisation, have been identified in the range of 1.5 10-6 rad/s to 2 10-7 rad/s, which is less than 5-7 percent of the seismic event amplitude. Besides, it was shown clearly that the two-antiparallel seismometers system also detected such events with the time and amplitude correlated with the data recorded by fiber-optic one, and only some mistake in the acquisition system limited their recording in the measurements made previously. -
L.R. Jaroszewicz, K. Stasiewicz, T.R. Woliński, K. Czupryński, P. Marć, A. Czapla, E. Nowinowski-Kruszelnicki, "Novel all in-line photonic crystal fiber interferometer with liquid crystal transducer", SPIE, 7004, (2008), 70046O
A novel in-line photonic crystal fiber interferometer, in the Sagnac configuration consisted of a fused photonic coupler and a liquid crystal transducer is proposed and demonstrated for the first time to our best knowledge. System optimization for 532 nm wavelength is based on properties of the liquid crystal mixture, infiltrating air-holes of the photonic crystal fiber protecting its endlessly single mode operation. The fundamental device properties for the different applied temperature is demonstrated and discussed.
Keywords: polarization, fiber-optic sensor, polarimeter
Keywords: polarization, fiber-optic sensor, polarimeter, interferometer
Keywords: polarization, fiber-optic sensor, interferometer, polarization theory
Keywords: phase unwrapping, fringr projection, three-dimenstion sensing, optical fiber interferometer
Keywords: fiber-optic, interferometry, polarisation properties, sensors
Keywords: pattern recognition, computer-generated holograms, optoelectronic system
Keywords: signal processing, neural network, semantic pattern recognition, classifiers, learning algorithms, optical fiber sensors
Keywords: pattern recognition, computer-generated hologram, artificial neural network, hybrid system, optimization, speckle patterns
Keywords: rotational waves, rotation seismograph systems, fiber-optic sensors
Keywords: optical fiber interferometry, laser Doppler velocimetry, vibrometer
Keywords: fiber-optic sensors, polarimeter, state and degree of polarisation
Keywords: interferometry, opical fiber devices, optical polarization, polarimetry
Keywords: fiber-optic devices, polarisation analyse, polarymetry, interferometry, automatic measurement
Keywords: opical fiber sensor, interferometry, rotational wave detection
Keywords: liquid crystal device, tunable fiber-optic elements, polarization phenomena, electro-optic effect
Keywords: tuned monochrome filters, Fabry-Perot interferometer, liquid crystal
Keywords: Haar wavelet, liquid crystalline polarizing filter, Berreman matrix
Keywords: tuned Fabry-Perot interferometer, Berreman matrix, refractive indices, refractive dispersion
Keywords: monitoring systems, neural networks, pattern recognition,, holographic ring-wedge detectors
Keywords: machine diagnostic, automatic image recognition, Fourier transform, neural network
Keywords: pattern recognition, computer-generated hologram, artificial neural network, hybrid system
Keywords:depolarization description, interferometry, optical fiber, polarization measurement
Keywords: simulation, fiber-optic interferometer design, polarization phenomenon
Keywords: optical coherent tomography, fiber-optic interferometer, short pulses laser system.
Keywords: fiber-optic elements, polarization, taper, technology.
Keywords: Haar wavelet, liquid crystal, edge detection, image processing, polarimetric imaging
Keywords: tuned monochrome filters, Fabry-Perot, liquid crystal
Keywords: fiberscope sensor, engine monitoring, image classification, neural network
Keywords: probabilistic neural networks, multilayer perceptions, image recognition,
Keywords: fiber optic sensor, rotational seismic wave, system calibration,
Keywords: data anlalysis, sensor, rotational seismic wave, system calibration,
Keywords: fiber-optic sensor, interferometry, rotational seismometer, polarization analyzer
Keywords: depolarization description, polarization, interferometry, optical fiber, polarization mode dispersion
Keywords: optical coherent tomography, fiber-optic interferometer, short pulses laser system
Keywords: rotation waves detection, optical fiber sensor, interferometry, filter design
Keywords: automatic image recognition, joint transform correlator
Keywords: depolarization description, polarization, interferometry, optical fiber, polarization mode dispersion
Keywords: rotational waves, rotation seismograph systems, fiber-optic sensors
Keywords: fiber-optic sensor, state and degree of polarisation, indication error, precision
Keywords: interferometry, optical fiber devices, optical polarization, polarimetry
Keywords: interferometric sensor, optical fiber sensor, rotational seismic events, calibration
Keywords: interferometry, polarisation, rotation, vibration
Keywords: polarization, interference, optical-fiber interferometry
Keywords: fibre-optic device, interferometric sensor, gyroscope, seismic rotation waves
Keywords: fiber-optic device, interferometric sensor, rotational seismic events
Keywords: fiber-optic device, polarization analyze, polarimetry, interferometry, uncertainty of measurement
Keywords: fiber-optic interferometric sensor, seismic rotational waves, measurement
Keywords: three-dimension sensing, fibre-optic interferometer, fringe projection
Keywords: seismic rotational waves, rotational seismometer, fiber-optic sensors, polarization
Keywords: digital holographic interferometry, holocamera, fiber optic, noise supression
Keywords: fiber-optic device, interferometric sensor, rotational seismic events
Keywords: fiber-optic device, interferometric sensor, rotational seismic events
Keywords: fiber-optic device, interferometric sensor, polarization investigation
Keywords: fiber-optic device, holographic systems
Keywords: fiber-optic sensors, seismic rotational events, polarimetry, interference
Keywords: fiber-optic sensors, polarizations, interference
Keywords: optical fiber, interferometer, demodulation technique
Keywords: optical miniaturized device, holography, microstructural measurement
Keywords: fibre-optic element, polarization, optical fiber coupler
Keywords: fibre-optic element, polarization, optical fiber coupler, photonics fiber elements
Keywords: optical fibre interferometer, numerical simulation, Sagnac interferometer
Keywords: fibre-optic device, interferometric sensor, earthquakes investigation, seismic rotational waves
Keywords: fibre-optic device, interferometric sensor, earthquakes investigation, seismic rotational waves
Keywords: fibre-optic device, interferometric sensor, earthquakes investigation
Keywords: OCT, FOCT, tomography, interferometer
Keywords: fibre-optic device, interferometric sensor, earthquakes investigation
Keywords: OCT, optical fibre coherence tomography, Michelson interferometer, Fizeau interferometer, pulse system
Keywords: seismology, instrumentation rotation events measurement
Keywords: interferometer, polarymetric sensor, new devices, LC photonic fiber