Open AccessSub-ppb-level CH4 detection by exploiting a low-noise differential photoacoustic resonator with a room-temperature interband cascade laser
Author(s) -
Hongfei Zheng,
Yihua Liu,
Haoyang Lin,
Ruifeng Kan,
Pietro Patimisco,
Angelo Sampaolo,
Marilena Giglio,
Wenguo Zhu,
Jianhui Yu,
Frank K. Tittel,
Vincenzo Spagnolo,
Zhe Chen
Publication year - 2020
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.391322
Subject(s) - optics , resonator , laser , materials science , wavelength , time delay and integration , noise (video) , cascade , detection limit , optoelectronics , relative intensity noise , photoacoustic spectroscopy , modulation (music) , physics , semiconductor laser theory , chemistry , acoustics , chromatography , artificial intelligence , computer science , image (mathematics)
An ultra-highly sensitive and robust CH 4 sensor is reported based on a 3.3 µm interband cascade laser (ICL) and a low-noise differential photoacoustic (PAS) cell. The ICL emission wavelength targeted a fundamental absorption line of CH 4 at 2988.795 cm -1 with an intensity of 1.08 × 10 -19 cm/molecule. The double-pass and differential design of the PAS cell effectively enhanced the PAS signal amplitude and decreased its background noise. The wavelength modulation depth, operating pressure and V-T relaxation promotion were optimized to maximize the sensor detection limit. With an integration time of 90 s, a detection limit of 0.6 ppb was achieved. No additional water or air laser cooling were required and thereby allowing the realization of a compact and robust CH 4 sensor.