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1

Tuning transfer function of fiber-optic Fabry–Pérot interferometer via introduction of birefringence in the cavity

Hirsch Marzena, Wierzba Paweł, Jędrzejewska-Szczerska Małgorzata

Optica Applicata

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2019

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Vol. 49, nr 2

241--248

EN

The study investigates the impact of birefringence exhibited by the cavity material of a fiber-optic Fabry–Pérot interferometer on its transfer function. The theoretical approach to analyze the effect of birefringence in the cavity of a plane Fabry–Pérot interferometer is described. The case of high- and low-finesse interferometer is investigated. It is shown that introduction of a birefringent medium of optimized parameters can be used to increase the density of interference fringes in certain wavelength range – the feature can be used either for reduction of the cavity length in an interferometric sensor or operation with sources of narrower spectral characteristics.

2

A Tiny Fabry–Perot Interferometer with Postpositional Filter for Measurement of the Thermospheric Wind

Wang H., Wang Y., Fu J.

Acta Geophysica

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2016

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Vol. 64, no. 6

2748--2760

EN

A tiny and low-cost ground-based Fabry–Perot interferometer (FPI) was designed using a filter behind etalon and Galilean telescope system for the thermospheric wind observation with OI 630.0 nm nightglow emissions (~250 km). Based on the instrument, experiments were carried out at Langfang (39.40° N, 116.65° E) site for a rough comparison and Kelan (38.71° N, 111.58° E) site for a detailed validation. Wind results of Langfang experiment are well consistent with measurements of two other FPIs deployed at Xinglong (40.40° N, 117.59° E) and Kelan which are retrieved by the American National Center for Atmospheric Research (A-NCAR). In Kelan experiment, the averaged wind deviation between our FPI and A-NCAR FPI is 11.8 m/s. The averaged deviation of wind measurement error between them is 2.9 m/s. The comparisons suggest good agreement. Then, the analysis of influencing factors was made. The center determination offset has an exponential relation with wind deviation, while the radius calculation offset is linear with wind deviation.

3

Measurement of dynamic strain using an optic fibre system in adaptive composite laminates with an integrated piezoelectric sensor/actuator

Ramos C. A., de Oliveira R., Marques A. T., Frazao O.

Optica Applicata

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2011

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Vol. 41, nr 1

79--88

EN

This study seeks the development of adaptive composites capable to monitor and actively damp vibrations. In the proposed material, vibrations measurements are performed by an embedded low finesse optical fibre extrinsic Fabry–Pérot interferometer, while active damping will be performed by embedded piezoelectric ceramics. This paper focuses on the development of the monitoring procedure. The proposed interrogation procedure for the low finesse optical fibre extrinsic Fabry–Pérot interferometer was successfully used to monitor the composite plate when submitted to four-point bending dynamic tests at different frequencies. The embedding of both sensing and actuating components in carbon-fibre reinforced composite laminates is also presented. In the case of the actuator, the efficiency of the embedding process was merely analysed from the capability of the piezoelectric ceramic to monitor dynamic strain of the composite using the PZT piezoelectric inverse effect.

4

Optyczny detektor skażeń HF, SO2, CO2, NO2 z wykorzystaniem interferometru Fabry'ego-Perot'a

Ławreńczyk J., Jakubowska M., Gallewicz W.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 10

67-70

PL

Prezentowanym urządzeniem jest detektor gazów. wykorzystujący pomiar absorpcji promieniowania podczerwonego, (ang. NDIR) identyfikacji skażeń gazami HF, SO2, CO2, NH3 oraz określenia stężenia tych gazów. Urządzenie jest przeznaczone do detekcji gazów spalinowych ze spalarni śmieci. Fizyczna, podstawa, działania urządzenia jest absorpcja promieniowania elektromagnetycznego. przez cząsteczki posiadające moment dipolowy zmieniający się podczas drgań, skutkiem tego promieniowanie o częstotliwości drgań własnych cząsteczki jest absorbowane.

EN

This particular device is a gas detector operating on the principle of infrared absorption (NDIR) is designed to identify the contamination gases HF, SO2, CO2, NH3, and determine the concentration of these gases. The device is intended for the detection of exhaust gases from waste incinerators. The physical operation of the device is based on the absorption of electromagnetic radiation by particles with a changing dipole moment during vibration, the effect of radiation on the frequency vibrations of a molecule is absorbed.

5

Raman spectra evaluation of the carbon layers with Voigt profile

Gołąbczak M., Konstantynowicz A.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

270-276

EN

Purpose: Recent use of Raman spectroscopy as the valuable tool for investigations of the content and state of different material samples is rapidly growing especially in the area of the DLC (Diamond-Like Carbon) layers investigation. Not only qualitative analysis but also quantitative is in the scope of this method which in turn demands use of precise mathematical tools for describing spectrograms. Design/methodology/approach: So-called Voigt profile establish basis for the relatively most precise shape-functions used for describing spectrogram shape. Voigt profile is the convolution of the very well known distribution functions: Gaussian distribution and Cauchy distribution (Lorentz distribution). Gaussian distribution is traditionally recognized as a tool for modeling multi-causal phenomena due to the Central Limit Theorem results. Cauchy distribution is recognized as modeling influence of the Fabry-Pérot interferometer (etalon) used for detection of the Raman spectrum. Findings: We present successful decomposition of the Raman spectra into elements: base function, peaks’ determination and etalon influence on spectral peaks’ shapes. Thorough numerical simulation of the Fabry-Pérot interferometer has been performed and identification of its accuracy parameter has been done when matching Voigt profile based function to the experimental data. Research limitations/implications: Good computational tools for generation of the Voigt profile, being not an analytical function itself and good understanding of mutual relationships between the Voigt profile and the Fabry-Pérot interferometer is of main interest for not only practical but also precise use this tool for quantitative analysis of Raman spectra. Practical implications: The main goal of our work has been the thorough preparation for future works with spectrum deconvolution allowing better resolution in determining Raman spectrum components. Originality/value: So far no proper attention has been paid to precise, quantitative analysis of the Raman spectra of the DLC layers.

6

Investigations of optical interferometric structures applied in toxic gas sensors

Opilski Z., Pustelny T., Maciak E., Bednorz M., Stolarczyk A., Jadamiec M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2005

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Vol. 53, nr 2

151-156

EN

In recent years organic semiconductors have been given attention in the field of active materials for gas sensor applications. In the paper the investigations of the optoelectronic sensor structure of ammonia were presented. The sensor head consists of polyaniline and Nafion layers deposited on the face of the telecommunication optical fiber. The elaborated sensor ructure in the form of Fabry-Perot interferometer is of the extremely small dimension - its thickness is of the order of 1 [mu]m. Many sensor structures of different combinations of the polyaniline and Nafion layers were constructed and investigated. The optimal solution seems to be the structures with small number of polianiline layers (up to three).

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.