Wyniki wyszukiwania - BazTech

1

Prospects for Solar and Space Weather Research with Polish Part of the LOFAR Telescope

Dąbrowski B. P., Krankowski A., Błaszkiewicz L., Rothkaehl H.

Acta Geophysica

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2016

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Vol. 64, no. 3

825--840

EN

The LOw-Frequency ARray (LOFAR) is a new radio interferometer that consists of an array of stations. Each of them is a phase array of dipole antennas. LOFAR stations are distributed mostly in the Netherlands, but also throughout Europe. In the article we discuss the possibility of using this instrument for solar and space weather studies, as well as ionosphere investigations. We are expecting that in the near future the LOFAR telescope will bring some interesting observations and discoveries in these fields. It will also help to observe solar active events that have a direct influence on the near-Earth space weather.

2

A suggestion of utilizing bimodal layers of the polymer SU8 for the purpose of monitoring the changes in the refractive index

Gut K.

Optica Applicata

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2012

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Vol. 42, nr 2

407-416

EN

The paper presents the results of investigations concerning the measurements of the refractive index and the thickness of planar waveguide structures, obtained by photopolymerization of the polymer SU8. In the paper, the mode sensitivity has been calculated as a function of the thickness in a bimodal structure. The differential interference has been analyzed, concerning the modes of the same types TE0-TE1 and TM0-TM1. The thickness of the layer has been determined when the interferometer is most sensitive to the changes in the refractive index.

3

Światłowodowy demodulator fazy : model i wyniki eksperymentalne

Hołdyński Z., Merta I., Jaroszewicz L. R., Świłło R.

Elektronika : konstrukcje, technologie, zastosowania

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2012

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Vol. 53, nr 11

46-47

PL

W pracy przedstawiono model i wyniki badań interferencyjnego światłowodowego demodulatora fazy w układzie interferometru Younga z dwuelementowym fotodetektorem w płaszczyźnie Fouriera. Oszacowano błąd metody pomiaru fazy i podano warunek jego minimalizacji w powiązaniu z parametrami geometrycznymi demodulatora pokazano związek odległości między fotodetektorami z liniowością światłowodowego demodulatora fazy. Wyniki eksperymentalne pozostają w wysokim stopniu korelacji z przyjętym modelem demodulatora fazy.

EN

In work we present fibre optics phase demodulator modeling and experimental results based on Young interferometrie configuration with bicell photodetector in Fourier focal plane. We experimentally estimated measurements' method errors and explained minimum condition of errors because of their directly connection with demodulator geometric parameters. We explained influence of gap size between photodetectors on linearization condition of phase demodulator. Experimental results are in high correlation with described model of phase demodulator.

4

Differential interference in a polymer waveguide

Gut K.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2011

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Vol. 59, nr 4

395-399

EN

The paper presents the results of investigations concerning the measurement of the refractive index and the thickness of planar waveguide structures, obtained by photo polymerization of the polymer SU8. In the paper the mode sensitivity has been calculated as a function of the thickness in a single-mode structure. The thickness of the layer has been determined in the case when the interferometer is most sensitive to changes of the refractive index.

5

Intruder localization and identification using fiber optic

Życzkowski M.

Molecular and Quantum Acoustics

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2008

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Vol. 29

193-198

EN

The ultimate goal in all fiber optic systems is to extract information about the mechanical perturbations. For example, this information may be the frequency dependent index of perturbation. For security systems we desire to detect and differentiate between different intruders based on the mechanical response. In this article classification architecture is developed. Emphasis is placed on the problem of feature extraction to reduce all spectral responses to several features allowing simple classification of different perturbation. The identification of specific intruder signals was investigated in the following application settings: interferometer Sagnac-Sagnac fiber optic sensor responses, interferometer Michelson-Sagnac fiber optic sensor responses, modalmetric fiber optic sensor responses. The field of signal processing techniques for fiber optic systems is relatively unexplored; however work has been reported in determining optimal techniques for demodulation, denoising, localization place of perturbance and identification kind of perturbation for specific, different fiber optic systems.

6

Accuracy improvement of bulk optical polarization interferometric sensors

Wierzba P., Kosmowski B. B.

Optica Applicata

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2005

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Vol. 35, nr 1

171-185

EN

Interferometric sensors using bulk optical components exhibit very high measurement resolution. In order to attain high accuracy, these sensors are often implemented as polarization interferometers, in which stable and well-defined states of polarization are maintained. Unwanted phenomena degrading accuracy of this class of sensors are disscused in the paper. Signal processing technique which improves accuracy of polarization interferometric sensors is presented. Its implementation using analogue circuits is discussed and a method of of improving its performance is devised.

7

System interferometryczny do badania drgań o dużych ampliudach

Borowicz L., Machalica P., Mocny W., Majkowski R.

Prace Przemysłowego Instytutu Elektroniki

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2001

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nr 143

35-50

PL

W artykule podaje się zastosowanie interferometru typu Twymana - Greena do pomiaru drgań o dużych amplitudach (znacznie przekraczających długość fali użytego promieniowania laserowego (lambda=632,8 nm). Zbadano, czy zastosowanie techniki zliczania kolejnych ekstremów oświetlenia pola interferencyjnego umożliwia również uzyskanie informacji o pozostałych parametrach ruchu, tj. o chwilowych wartościach prędkości i przyspieszenia, bez uciekania się do technik wykorzystujących zjawisko Dopplera. Wskazano na możliwość detekcji punktów zwrotu wektora przemieszczenia przy wykorzystaniu jednego tylko toru pomiarowego. Opisano funkcje, jakie powinien spełniać blok przetwarzania zarejestrowanych danych.

EN

The paper refers to the use of an interferometer of Twymann-Green type, to measure vibrations of high amplitude, i.e. that substantially exceed the wavelength of laser radiation(lambda=632.8 nm). It was tested whether the use of technique of counting subsequent extremities of interference field also makes it possible to obtain information on other movement parameters, i.e. on instantaneous values of speed and acceleration, without referring to techniques using Doppler effect. It was pointed out that it is possible to detect turning points of dislocation vector using just one slotted line. Functions were described, which should characterise the processing block of data registration.