Open AccessOff-beam QEPAS sensor using an 11-μm DFB-QCL with an optimized acoustic resonator
Author(s) -
Roman Rousseau,
Zeineb Loghmari,
M. Bahriz,
Kaïm Chamassi,
R. Teissier,
А. Н. Баранов,
A. Vicet
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.007435
Subject(s) - photoacoustic spectroscopy , quantum cascade laser , optics , materials science , resonator , microphone , photoacoustic effect , time delay and integration , beam (structure) , optoelectronics , microelectromechanical systems , laser , acoustics , physics , sound pressure
An off-beam quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor was designed for ethylene detection using a distributed-feedback quantum cascade laser (QCL) operating in the mid-infrared around 11 μm. The acoustic microresonator configuration was experimentally optimized using an original open-cell photoacoustic setup with a MEMS microphone. Correction factors based on theoretical acoustic models were introduced in order to accurately describe the response of millimeter-sized acoustic resonators. The optimized QEPAS sensor exhibited a limit of detection of 60 ppb for 60 s integration, giving a NNEA of 4.8 × 10 -8 W·cm -1 ·Hz -0.5 .