Signal processing system in cavity enhanced spectroscopy

• Autorzy: Wojtas J. , Bielecki Z.
• Języki publikacji: EN

Abstrakty

EN

The paper presents a signal processing system used for nitrogen dioxide detection employing cavity enhanced absorption spectroscopy. In this system, the absorbing gas concentration is determined by the measurement of a decay time of a light pulse trapped in a cavity. The setup includes a resonance optical cavity, which was equipped with spherical and high reflectance mirrors, the pulsed diode laser (414 nm) and electronic signal processing system. In order to ensure registration of low-level signals and accurate decay time measurements, special preamplifier and digital signal processing circuit were developed. Theoretical analyses of main parameters of optical cavity and signal processing system were presented and especially signal-to-noise ratio was taken into consideration. Furthermore, investigation of S/N signal processing system and influence of preamplifier feedback resistance on the useful signal distortion were described. The aim of the experiment was to study potential application of cavity enhanced absorption spectroscopy for construction of fully optoelectronic NO₂ sensor which could replace, e.g., commonly used chemical detectors. Thanks to the developed signal processing system, detection limit of NO₂ sensor reaches the value of 0.2 ppb (absorption coefficient equivalent = 2.8 x 10 ⁻⁹ cm⁻¹ ).

Słowa kluczowe

EN

CEAS; Council of European Aerospace Societes; NO2 sensor; signal processing system; PMT preamplifier; noise measurements

• Wydawca: Stowarzyszenie Elektryków Polskich ; Polska Akademia Nauk ; Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Opto-Electronics Review
• Rocznik: 2008
• Tom: Vol. 16, No. 4
• Strony: 420--427
• Opis fizyczny: Bibliogr. 11 poz., il., wykr.

Twórcy

autor

Wojtas J.

autor

Bielecki Z.

• Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland,

Bibliografia

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• 3. J. Wojtas, A. Czyżewski, T. Stacewicz, Z. Bielecki, and J. Mikołajczyk, “Cavity enhanced spectroscopy for NO2 detection”, Proc. SPIE 5954, 174-178 (2005).
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