Open AccessQuartz-enhanced photoacoustic detection of ethylene using a 105 μm quantum cascade laser
Author(s) -
Zhen Wang,
Zhili Li,
Wei Ren
Publication year - 2016
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.24.004143
Subject(s) - quantum cascade laser , photoacoustic spectroscopy , materials science , detection limit , optics , laser , torr , wavelength , resonator , quartz , calibration , optoelectronics , chemistry , physics , chromatography , quantum mechanics , composite material , thermodynamics
A quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor has been developed for the sensitive detection of ethylene (C2H4) at 10.5 µm using a continuous-wave distributed-feedback quantum cascade laser. At this long-wavelength infrared, the key acoustic elements of quartz tuning fork and micro-resonators were optimized to improve the detection signal-to-noise ratio by a factor of >4. The sensor calibration demonstrated an excellent linear response (R2>0.999) to C2H4 concentration at the selected operating pressure of 500 and 760 Torr. With a minimum detection limit of 50 parts per billion (ppb) achieved at an averaging time of 70 s, the sensor has been deployed for measuring the C2H4 efflux during the respiration of biological samples in an agronomic environment.