Results 141 to 150 of about 1,073 (164)

QEPAS detector for rapid spectral measurements

Applied Physics B, 2010
A quartz enhanced photoacoustic spectroscopy sensor designed for fast response was used in combina- tion with a pulsed external cavity quantum cascade laser to rapidly acquire gas absorption data over the 1196- 1281 cm −1 spectral range. The system was used to measure concentrations of water vapor, pentafluoroethane (freon- 125), acetone, and ethanol ...
A. A. Kosterev, P. R. Buerki, L. Dong, M. Reed, T. Day, F. K. Tittel   +5 more
openaire   +1 more source

GaSb Diode Lasers for QEPAS Sensor Applications

Conference on Lasers and Electro-Optics, 2018
Newly developed tunable single mode laser diodes based on GaSb material system in the wavelength range 1.6 μm ≤ λ ≤ 4 μm are combined with the QEPAS technique for trace gas detection.
Tobias Milde, Morten Hoppe, Hervé Tatenguem, Wolfgang Schade, Joachim Sacher   +4 more
openaire   +1 more source

QEPAS methane sensor performance for humidified gases

Applied Physics B, 2008
A trace gas sensor based on quartz enhanced photoacoustic spectroscopy (QEPAS) was evaluated using humidified nitrogen samples and ambient air. Relaxation processes following vibrational excitation of 2ν3 state of CH4 were investigated. Sensor performance at different gas pressures could be predicted based on a developed kinetic model.
A.A. Kosterev, Y.A. Bakhirkin, F.K. Tittel, S. McWhorter, B. Ashcraft   +4 more
openaire   +1 more source

Improved IP-QEPAS sensor based on cylindrical cavity enhancement

Infrared Physics & Technology, 2021
Abstract In this paper, a cylindrical cavity based in-plane quartz-enhanced photoacoustic spectroscopy (IP-QEPAS) was demonstrated for the first time. The cylindrical cavity was designed by theoretical mode and used as a resonator to improve the strength of acoustics wave.
Yinghao Hong, Shunda Qiao, Yufei Ma
openaire   +1 more source

Mid-infrared fiber-coupled QCL-QEPAS sensor

Applied Physics B, 2013
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SPAGNOLO, Vincenzo Luigi, Patimisco P., Borri S., Scamarcio G., Bernacki B. E., Kriesel J.   +5 more
openaire   +2 more sources

Acetylene-enhanced methane-QEPAS sensing

Optics Letters
Methane (CH4), as a critical greenhouse gas and explosive hazard, demands highly sensitive detection for environmental monitoring and industrial safety. To address the limitation of its slow relaxation in quartz-enhanced photoacoustic spectroscopy (QEPAS), this paper reported a novel acetylene (C2H2)-enhanced QEPAS technique for CH4 sensing for the ...
Jin Sun, Ying He, Shunda Qiao, Chu Zhang, Yufei Ma   +4 more
openaire   +1 more source

QEPAS sensor for breath analysis: a behavior of pressure

Applied Optics, 2018
The measurement of trace gases has increasingly become a key technique in healthcare and other medical applications. Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a suitable method that can provide the required characteristics in such applications for a comparatively low cost and small size.
Tobias Milde, Morten Hoppe, Herve Tatenguem, Mario Mordmüller, James O’Gorman, Ulrike Willer, Wolfgang Schade, Joachim Sacher   +7 more
openaire   +2 more sources

Optimized DFB laser diodes for a Butterfly QEPAS Sensor

OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES), 2021
Optimized DFB lasers are presented. Results for the performance and its suitability for detecting trace gases are shown. We present our new QEPAS compact detection unit where everything is integrated into 14-pin butterfly housing.
Tobias Milde, Morten Hoppe, Hervé Tatenguem, Sebastian Schmidtmann, Christian Assmann, Martin Honsberg, Joachim Sacher   +6 more
openaire   +1 more source

Modeling and Design of a Semi-Integrated QEPAS Sensor

Journal of Lightwave Technology, 2021
Quartz enhanced photo acoustic spectroscopy (QEPAS) has gained a growing interest in recent years for gas sensing technology because of the high sensitivity provided by sharp resonant tuning forks (QTFs) exploited as piezoelectric sound wave detectors; and the modularity, compactness, and robustness of the sensors.
Martino De Carlo, Giansergio Menduni, Angelo Sampaolo, Francesco De Leonardis, Vincenzo Spagnolo, Vittorio M. N. Passaro   +5 more
openaire   +1 more source

Remote, distributed gas sensor based on FEW-QEPAS

Conference on Lasers and Electro-Optics, 2018
A remote, distributed gas sensing using fiber evanescent wave quartz-enhanced photoacoustic spectroscopy (FEW-QEPAS) technique was demonstrated. A 3 km single mode fiber with multiple tapers was employed to perform long distance, distributed gas measurements.
Ying He, Yufei Ma, Yao Tong, Xin Yu, Frank K. Tittel   +4 more
openaire   +1 more source