title: Absorption line profile recovery based on TDLS and MEMS micro-mirror for photoacoustic gas sensing.
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 (C2H2) in a nitrogen host gas. The laser diode wavelength is swept across the P17 absorption line of acetylene at 1535.4 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.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. dawnjlu@gmail.com
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Norhana
authors.initials: N
authors.lastname: Arsad
authors.forename: George
authors.initials: G
authors.lastname: Stewart
authors.forename: Graham
authors.initials: G
authors.lastname: Thursby
authors.forename: Deepak
authors.initials: D
authors.lastname: Uttamchandani
authors.forename: Brian
authors.initials: B
authors.lastname: Culshaw
authors.forename: Wang
authors.initials: W
authors.lastname: Yi-ding