Results 161 to 170 of about 825 (180)
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GaSb Diode Lasers for QEPAS Sensor Applications
Conference on Lasers and Electro-Optics, 2018Newly 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 +4 more
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A new Method to Determine the Resonance Frequency in QEPAS
Conference on Lasers and Electro-Optics, 2018We present a novel method to determine the resonance frequency and Q factor of a quartz tuning fork (QTF) in quartz-enhanced photoacoustic spectroscopy (QEPAS) in a few seconds. A CHIRP modulates a laser diode.
Philipp Breitegger +2 more
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A Dual-Gas Sensing System Based on QEPAS and LITES
IEEE Sensors JournalShaoqiang Bi, Jingqi Shi, Yiyang Zhao
exaly +2 more sources
Remote, distributed gas sensor based on FEW-QEPAS
Conference on Lasers and Electro-Optics, 2018A 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 +4 more
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Pivotal techniques evaluation in QEPAS system for engineering applications
Measurement, 2019Abstract Efforts were made in this study to evaluate a series of pivotal techniques in standard quartz tuning fork (QTF) based quartz enhanced photoacoustic spectroscopy (QEPAS) systems for engineering applications. In current QEPAS systems, a scanning ramp combined with high frequency sinusoidal signal is used to drive the light source for ...
Fupeng Wang +4 more
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NIR diode laser-based QEPAS for acetylene detection
SPIE Proceedings, 2012Quartz-enhanced photoacoustic spectroscopy with a near infrared distributed feedback diode laser at 1.53 μm is demonstrated for acetylene detection at atmospheric pressure and room temperature. The P(9) absorption line in the ν1+ν3 band of C2H2 is selected for light absorption and photoacoustic pressure wave excitation.
Yingchun Cao, Wei Jin, Hoi Lut Ho
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QEPAS for chemical analysis of multi-component gas mixtures
Applied Physics B, 2010A gas sensor based on quartz-enhanced photoacoustic spectroscopy and using near-infrared, fiber-coupled diode lasers as an excitation source was developed for chemical analysis of gas mixtures containing H2S, CO2, and CH4 at concentrations from 0 to 100%. Analysis of physical phenomena affecting the sensor operation is performed, the sensor performance
A. A. Kosterev +4 more
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[Experimental research on optimization of QEPAS based spectrophone].
Guang pu xue yu guang pu fen xi = Guang pu, 2015The present paper studied the impact of geometry dimensions, located angle and detection position of a quartz tuning fork (QTF) on the sensitivity of QEPAS system. Ten kinds of QTFs were employed to compare the sensitivity with each other, and the results show that the QTF with a wedge-shape top obtains a higher quality factor and turns to be 50% more ...
Hua-Dan, Zheng +7 more
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Compact QEPAS CO2 sensor system using a quartz tuning fork-embedded and in-plane configuration
Optics and Laser Technology, 2023Dehua Zhu, Juncheng Lu
exaly
Improved IP-QEPAS sensor based on cylindrical cavity enhancement
Infrared Physics and Technology, 2021exaly