Results 71 to 80 of about 218 (120)

Purely wavelength- and amplitude-modulated quartz-enhanced photoacoustic spectroscopy

Optics Express, 2016
We report here on a quartz-enhanced photoacoustic (QEPAS) sensor employing a quantum cascade laser (QCL) structure capable of operating in a pure amplitude or wavelength modulation configuration. The QCL structure is composed of three electrically independent sections: Gain, Phase (PS) and Master Oscillator (MO).
Patimisco, Pietro, Sampaolo, Angelo, Bidaux, Yves, Bismuto, Alfredo, Scott, Marshall, Jiang, James, Muller, Antoine, Faist, Jerome, Tittel, Frank K., SPAGNOLO, Vincenzo Luigi   +9 more
openaire   +4 more sources

Quartz tuning fork embedded off-beam quartz-enhanced photoacoustic spectroscopy

Optics Letters, 2019
In order to achieve a high acoustic coupling strength and detection sensitivity and to simplify the assembly and alignment process in quartz-enhanced photoacoustic spectroscopy (QEPAS) technique, a novel quartz tuning fork (QTF) embedded off-beam QEPAS (E-OB-QEPAS) spectrophone was proposed.
Lien Hu, Chuantao Zheng, Jie Zheng, Yiding Wang, Frank K. Tittel   +4 more
openaire   +2 more sources

Planar Laser-Based QEPAS Trace Gas Sensor

Sensors, 2016
A novel quartz enhanced photoacoustic spectroscopy (QEPAS) trace gas detection scheme is reported in this paper. A cylindrical lens was employed for near-infrared laser focusing.
Yufei Ma, Ying He, Cheng Chen, Xin Yu, Jingbo Zhang, Jiangbo Peng, Rui Sun, Frank K. Tittel   +7 more
doaj   +1 more source

Spatially engineered optical–acoustic matching in quartz-enhanced photoacoustic spectroscopy

Photoacoustics
Quartz-enhanced photoacoustic spectroscopy (QEPAS) offers high sensitivity for trace-gas detection, but its performance is often limited by a spatial mismatch between distributed photoacoustic excitation and the intrinsic sensitivity region of the quartz
Ruyue Cui, Wenfei Han, Chenglong Wang, Chunxia Li, Yingzhang Ren, Xinran Li, Jiale Xu, Vincenzo Spagnolo, Weidong Chen, Hongpeng Wu, Lei Dong   +10 more
doaj   +1 more source

Harmonic phase-sensitive detection for quartz-enhanced photoacoustic-thermoelastic spectroscopy

Photoacoustics
Quartz tuning fork (QTF)-based techniques of photoacoustic spectroscopy and thermoelastic spectroscopy play a significant role in trace gas sensing due to unique high sensitivity and compactness.
Mengpeng Hu, Dongqing Zhang, Hui Zhang, Yu Liu, Weibiao Wang, Qiang Wang   +5 more
doaj   +1 more source

A Miniaturized QEPAS Trace Gas Sensor with a 3D-Printed Acoustic Detection Module

Sensors, 2017
A 3D printing technique was introduced to a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor and is reported for the first time. The acoustic detection module (ADM) was designed and fabricated using the 3D printing technique and the ADM volume ...
Xiaotao Yang, Youhong Xiao, Yufei Ma, Ying He, Frank K. Tittel   +4 more
doaj   +1 more source

Dual-Component Beat-Frequency Quartz-Enhanced Photoacoustic Spectroscopy Gas Detection System

Photonics
This study designed and validated a dual-component beat-frequency quartz-enhanced photoacoustic spectroscopy (BF-QEPAS) gas detection system utilizing time-division multiplexing (TDM).
Hangyu Xu, Yiwen Feng, Zihao Chen, Zhenzhao Zhuang, Jinbao Xia, Yiyang Zhao, Sasa Zhang   +6 more
doaj   +1 more source

Effect of gas turbulence in quartz-enhanced photoacoustic spectroscopy: A comprehensive flow field analysis

Photoacoustics
Here we present a computational and experimental fluid dynamics study for the characterization of the flow field within the gas chamber of a Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) sensor, at different flow rates at the inlet of the chamber ...
Andrea Zifarelli, Giuseppe Negro, Lavinia A. Mongelli, Angelo Sampaolo, Ezio Ranieri, Lei Dong, Hongpeng Wu, Pietro Patimisco, Giuseppe Gonnella, Vincenzo Spagnolo   +9 more
doaj   +1 more source

Ultra-highly sensitive dual gases detection based on photoacoustic spectroscopy by exploiting a long-wave, high-power, wide-tunable, single-longitudinal-mode solid-state laser

Light: Science & Applications
Photoacoustic spectroscopy (PAS) as a highly sensitive and selective trace gas detection technique has extremely broad application in many fields. However, the laser sources currently used in PAS limit the sensing performance. Compared to diode laser and
Shunda Qiao, Ying He, Haiyue Sun, Pietro Patimisco, Angelo Sampaolo, Vincenzo Spagnolo, Yufei Ma   +6 more
doaj   +1 more source

Quartz-enhanced laser spectroscopy sensing

Light: Science & Applications
Gas sensing technology is widely applied in various fields, including environmental monitoring, industrial process control, medical diagnostics, safety warnings, and more.
Shunda Qiao, Xiaonan Liu, Ziting Lang, Ying He, Weidong Chen, Yufei Ma   +5 more
doaj   +1 more source