Absorption line profile recovery based on TDLS and MEMS micro-mirror for photoacoustic gas sensing

Li Li, Norhana Arshad, George Stewart, Graham Thursby, Deepak Uttamchandani, Brian Culshaw, YD Yang

Research output: Contribution to journalArticle

Abstract

A novel and efficient absorption line recovery technique is presented. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection. Tunable diode laser spectroscopy (TDLS) and photoacoustic spectroscopy (PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile. The target gas is 0. 01% acetylene (C(2)H(2)) in a nitrogen host gas. The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535. 4 nm by a current ramp, and an erbium-doped fibre amplifier (EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio (SNR). A SNR of about 35 is obtained with 100 mW laser power from the EDFA. Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.
Original languageEnglish
Pages (from-to)1814-1818
Number of pages5
JournalSpectroscopy and Spectral Analysis
Volume31
Issue number7
DOIs
Publication statusPublished - 1 Jul 2011

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Keywords

  • photo-acoustic gas sensing
  • micro-electro-mechanical-systems (MEMS)
  • laser intensity modulation
  • absorption line profile recovery
  • tunable diode laser spectroscopy

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