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1

Mid-wave infrared liquid crystal shutter for breathalyzer applications

Piecek W., Jaroszewicz L., Miszczyk E., Raszewski Z., Mrukiewicz M., Kula P., Jasek K., Perkowski P., Nowinowski-Kruszelnicki E., Zieliński J., Kędzierski J., Olifierczuk M., Chodorow U., Morawiak P., Mazur R., Kowiorski K., Harmata P., Herman J.

Opto-Electronics Review

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2017

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Vol. 25, No. 2

103--109

EN

There exists a problem with an in situ diagnostics of contamination of ethyl alcohol in a human being exhaled air. When ethyl alcohol in a mouth blowing (in a gaseous state) exists, the characteristic C-H stretch absorption bands in CH3 and CH2 functional groups in ethanol (CH3CH2OH) appear at a wave length of λ = 3.42 µm. To investigate the presence of ethyl alcohol in exhaled human air, the light beam of λ = 3.42 µm is passing through an air sample. If one alternately measures the intensity of the investigated beam and the reference, a percentage of ethanol in the air sample can be estimated using a sensitive nondispersive infrared (NDIR) system with a stable operating flow mass detector. To eliminate a mechanical chopper and noise generating stepper motors, a photonic chopper as a liquid crystal shutter for λ = 3.42 µm has been designed. For this purpose, an innovative infrared nematic liquid crystal mixture was intentionally prepared. The working mixture was obtained by a selective removal of C-H bonds and its exchange by heavier polar substituents, what ensures a lack of absorption band of C-H bonds. The paper presents theory, concept and final experimental results of the infrared nematic liquid crystals mixture and the liquid crystal shutter for breathalyzer applications.

2

Transparent laser damage resistant nematic liquid crystal cell “LCNP3”

Raszewski Z., Piecek W., Jaroszewicz L., Dąbrowski R., Nowinowski-Kruszelnicki E., Soms L., Olifierczuk M., Kędzierski J., Morawiak P., Mazur R., Miszczyk E., Mrukiewicz M., Kowiorski K.

Opto-Electronics Review

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2014

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Vol. 22, No. 3

196-200

EN

There exists the problem in diagnostics of dense plasma (so-called Thomson diagnostics). For this purpose the plasma is illuminated by series of high energy laser pulses. The energy of each separate pulse is as large as 3 J, so it is impossible to generate a burst of such pulses by a single laser. In this situation, the pulses are generated by several independent lasers operating sequentially, and these pulses are to be directed along the same optical path. To form an optical path with ʎ = 1.064 μm and absolute value of the laser pulse energy of 3 J, a special refractive index matched twisted Nematic Liquid Crystal Cell of type LCNP3, with switching on time ƮON smaller than 3 μs was applied.

3

Measurement of elastic constants of nematic liquid crystals with use of hybrid in-plane-switched cell

Nowinowski-Kruszelnicki E., Kędzierski J., Raszewski Z., Jaroszewicz L., Kojdecki M. A., Piecek W., Perkowski P., Olifierczuk M., Miszczyk E., Ogrosnik K., Morawiak P.

Opto-Electronics Review

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2012

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Vol. 20, No. 3

255-259

EN

A new method for quick and pretty accurate measurements of splay, twist and bend elastic constants of nematic liquid crystals is experimentally verified. The main concept relies on exploiting only the electric field and determining magnitudes of nematic elastic constants from threshold fields for Freedericksz transitions in only one hybrid in-plane-switched cell. In such cell the deformations of an investigated liquid crystal are controlled by three separated pairs of electrodes confining measurement domains. In two of them inter-digital electrodes are mounted on one cell cover. Splay, twist and bend elastic constants can be measured by a proper choice of electrodes' configuration together with orienting cover coatings (without applying magnetic fields). In this paper, we describe layout of our cells and results of experimental tests by using different liquid crystals: 5CB and 6CHBT (with positive dielectric anisotropy), Demus' esters (with negative dielectric anisotropy) and new liquid crystals mixtures produced in our university.

4

Liquid crystal cell for space-borne laser rangefinder to space mission applications

Nowinowski-Kruszelnicki E., Jaroszewicz L., Raszewski Z., Soms L., Piecek W., Perkowski P., Kędzierski J., Dąbrowski R., Olifierczuk M., Garbat K., Miszczyk E.

Opto-Electronics Review

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2012

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Vol. 20, No. 4

315-322

EN

Liquid crystal cell (LCC) for space-borne laser rangefinder to space mission applications was developed, manufactured and tested under cooperation between Military University of Technology (MUT) in Poland and Vavilov State Optical Institute (Vavilov SOI) in Russia. LCC operates in twisted nematic mode, commutating the polarization plane of a laser beam working at 1.064 µm and the energy density not smaller than 0,15 J/cm² at the pulse duration about 8 ns. The transmission of LCC is not smaller than 95% at the aperture diameter not less than 15 mm. Switching on and switching off times in a 2.5-µm thick LCC driven by voltage of 10 V are not larger than 0.7 ms and 7 ms, respectively, in the operating temperature range from 20°C to 40°C. The LCCs developed in MUT were positively tested under space requirements in Vavilov SOI.

5

High birefringence liquid crystal mixtures for electro-optical devices

Nowinowski-Kruszelnicki E., Kędzierski J., Raszewski Z., Jaroszewicz L., Kojdecki M., Piecek W., Perkowski P., Garbat K., Olifierczuk M., Sutkowski M., Ogrodnik K., Morowiak P., Miszczyk E.

Optica Applicata

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2012

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Vol. 42, nr 1

167--180

EN

High-birefringence nematic liquid crystals recently developed in the Military University of Technology (Poland) are examined for selected physical properties. In particular, for six liquid crystal mixtures there were determined: two components of dielectric permittivity for voltage frequencies in the range from 10 Hz to 10 MHz; rotational viscosity; splay, twist and bend elastic constants; ordinary and extraordinary refractive indices for light wavelengths in the range from 0.3 ?m to 1.6 ?m. The properties are discussed in terms of applicability of the new liquid crystals to electro-optical devices.

6

Usefulness of the fiber-optic interferometer for the investigation of the seismic rotation waves

Jaroszewicz L., Krajewski Z., Teisseyre R.

Optica Applicata

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2005

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Vol. 35, nr 2

383-394

EN

In the paper 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 direct seismic rotation waves detection. The paper describes the design based on a well-known optical gyroscope configuration but with its optimization for its optimization for detection the absolute rotation, only. 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.

7

Tuned liquid crystalline interferometer analysis by means of generalised Berreman matrix

Walczak A., Nowinowski-Kruszelnicki E., Jaroszewicz L., Marciniak P.

Opto-Electronics Review

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2002

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Vol. 10, No. 1

69-73

EN

The analysis of the tuned, liquid crystalline Fabry-Perot interferometer (FPTI) has been done by means of 4 x 4 matrix. Wide-ange 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 FPTI parameters has been described in detail. Special attention has been paid to dispersion of the LC' refraction indices as a factor of spectral FPFI' properties.

8

Application of Fiber-Optic Sagnac Interferometer for Detection of Rotational Seismic Events

Jaroszewicz L., Krajewski Z., Świłło R.

Molecular and Quantum Acoustics

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2001

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Vol. 22

133-144

EN

A new area of fiber-optic Sagnac interferometer application is presented and discussed. The fiber-optic sensor described in the paperm 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 cenversion for rotation ac give an advantage for this system in compare to other rotational seismometers, which calculate rotational events in indirect ways. The comparison of data from th described fiber-optic rotation seismometer and two antiparallel pendulum seismometers are also presented.

9

Światłowodowe czujniki inteligentne : obecny stan rozwoju

Jaroszewicz L.

Elektronika : konstrukcje, technologie, zastosowania

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2001

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Vol. 42, nr 2

7-11

PL

W pracy przedstawiono zagadnienia związane z zastosowaniem włókien światłowodów jako podstawowego elementu czujnikowego nowej rodziny struktur określanych mianem inteligentnych. Bazując na omówieniu idei powyższych struktur, starano się nakreślić główne problemy, których rozwiązanie powinno doprowadzić do ich konstrukcji w niedalekiej przyszłości. W tym celu praca omawia podstawowe zagadnienia dotyczące ciągłego nadzoru prac układów na bazie zastosowania czujników światłowodowych.

EN

The application of optical fiber technology as the basic sensors in intelligent materials is presented in paper. The current R&D states as well as the main problems, which should be solved before development real structures in near future, are widely described. The basic issues connected with system monitoring on fiber-optic sensor basis are also described.

10

Kierunki rozwoju czujników światłowodowych

Jaroszewicz L.

Prace Naukowe Politechniki Warszawskiej. Konferencje

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1999

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z. 18

5-16

PL

W pracy przedstawiono główne kierunki rozwoju czujników światłowodowych. Omówienie dokonano głównie na bazie analizy materiałów opublikowanych w tomach kolejnych trzynastu międzynarodowych konferencji czujników światłowodowych, ze szczególnym uwzględnieniem ostatnich pięciu lat. Jako główne wyodrębniono i omówiono układy: giroskopu światłowodowego, detektora pola elektromagnetycznego, czujnika z rozłożonym polu detekcji oraz innych układów stosujących w swej konstrukcji światłowodowe siatki Bragga.

11

Sensing applications of fiber-optic Sagnac interferometer.

Jaroszewicz L., Kieżun A., Świłło R.

Optica Applicata

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1999

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Vol. 29, nr 1-2

139-162

EN

The various possible applications of the fiber-optic Sagnac interferometer as a sensor of physical fields are presented. The use of the Segnac interferometer as an optical gyroscope for an investigation of show-speed rotational platforms and a construction of distributed security system are described. The possibility of applying a modified system for measurement of nanometer vibrations and parameters of the in-ine fiber-optic polarizer, phase and polarisation modular are also presented. Finally, the usability of the Sagnac interferometer as a fiber-optic ellipsometer is described.

12

In-Line fiber-optic biconical taper polarizer.

Kieżun A., Jaroszewicz L., Świłło R.

Optica Applicata

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1999

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Vol. 29, nr 1-2

163-169

EN

The construction of the in-line fiber-optic polarizer is presented. This element based on the biconical taper structure is positioned on a metal layer. the four-layer planar structure has been used for theoretical investigation of polarizer action. The theoretical results have been compared with experimental investigation of manufactured elements. The technological set-up for the polarizer preparation is also shown. The polarizers have been made for 0.33 and 1.300 mm wavelenghths. The first of them has a typical extinction ratio of 25dB with an attenuation of guided mode of 3dB. The second one has typical extinction ratio of 30 dB or more, with an attenuation of the desired polarisation of about 2 dB.

13

Application of the Fourier transform to fibre-optic sensor recognition.

Merta I., Jaroszewicz L., Kieżun A.

Optica Applicata

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1999

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Vol. 29, nr 1-2

171-179

EN

The construction of the fibre-optic sensor of external perturbations and results of the relevant 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 considered 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 a result of a suitable process of network training, a possibility o recognizing the perturbation has emerged, which made it possible to avoid troublesome analysis of intermode interactions.

14

Polarimetric Detection Setup for Fibre Sensors

Kieżun A., Jaroszewicz L.

Molecular and Quantum Acoustics

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1999

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Vol. 20

109-113

EN

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.

15

Analysis of the reasons of angular velocity oscilations in a single-stage slow-speed platform

Szelmanowski A., Jaroszewicz L.

Journal of Technical Physics

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1998

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Vol. 39, no 2

261-274

EN

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 basic of simulation, the possibilities to obtain a smooth rotary motion have been analysed for a very low angular velocity of the order that of Earth revolution. In the experimental part, the application of a fibre optic gyroscope experimental verification of theoretical results is presented.