Results 191 to 200 of about 2,335 (228)

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

Towards Hydrogen Purity Monitoring: Investigating Quartz Tuning Fork Resonance and Developing a QEPAS-Based Sensor for NH3 Detection

Optica Sensing Congress 2025 (AIS, Sensors, QSM)
Hydrogen is a promising energy carrier for reducing carbon emissions, but its environmental benefits depend on purity, as fuel cell performance deteriorates due to contaminants generated during production.
A. Zifarelli, C. Feng, G. Menduni, Lei Dong, H. Wu, V. Spagnolo, P. Patimisco   +6 more
semanticscholar   +1 more source

Optimization of QEPAS Sensing Performance via Numerical Simulation and Experimental Measurement

Microwave and optical technology letters (Print)
Quartz tuning forks (QTFs) play a critical role in quartz‐enhanced photoacoustic spectroscopy (QEPAS). Theoretical analysis and simulation of QTF dimensions are essential for guiding sensor design, as they directly influence QEPAS signal performance ...
Yingchao Xie, Hongji Liu, Hao Xiong, Gaopeng Lu, Guishi Wang, Kun Liu   +5 more
semanticscholar   +1 more source

Numerical modeling and performance optimization of QEPAS spectrophone

SPIE Proceedings, 2012
The spectrophone performance for QEPAS is numerically investigated by using a finite element method. The effect of varying system parameters such as the excitation frequency, relative position between the acoustic resonant tubes and the quartz tuning fork, and the dimensions of resonant tubes are examined A pair of rigid tubes, each with a length of ...
Yingchun Cao, Wei Jin, Hoi Lut Ho
openaire   +1 more source

Dual-Gas Intra-Cavity QEPAS Sensor Based on Frequency Division Multiplexing Using Two Acoustic Microresonators

Journal of Lightwave Technology
A dual-gas intra-cavity quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on frequency division multiplexing (FDM) of a quartz tuning fork (QTF) using two acoustic microresonators (AmRs) was demonstrated in this paper.
Heng Zhang, Shaoqiang Bi, Jing Zhao, Yiyang Zhao, L. Qin, Jingqi Shi, Yulong Fu, Zongliang Wang   +7 more
semanticscholar   +1 more source

NIR diode laser-based QEPAS for acetylene detection

SPIE Proceedings, 2012
Quartz-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
openaire   +1 more source

Two-Component Gas Sensor of Time-Division Multiplexing Technique Based on QEPAS and LITES

IEEE Photonics Technology Letters
A two-component gas sensor based on Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) and Light-Induced Thermoelastic Spectroscopy (LITES) was realized by the time-division multiplexing technique. Two off-beam acoustic microresonator (AMRs) were used in
L. Qin, Shaoqiang Bi, Ran Chen, Yiyang Zhao, Jingqi Shi, Heng Zhang, Zongliang Wang   +6 more
semanticscholar   +1 more source

Integrated Multiexcitation Dual-Spectroscopy Detection Technique Based on QEPTS and QEPAS

IEEE Sensors Journal
A multiexcitation quartz-enhanced photoacoustic spectroscopy (QEPAS) and photothermal spectroscopy integrated detection structure are introduced. A laser beam incident at a certain angle is obtained by tilting the fiber optic collimator (FC), and two ...
Jing Zhao, Heng Zhang, Yulong Fu, L. Qin, Jingqi Shi, Yiyang Zhao, Zongliang Wang   +6 more
semanticscholar   +1 more source

Part-per-Billion (Ppb)-Level Acetylene Sensor Employing Optical Quartz Enhanced Photoacoustic Spectroscopy (QEPAS) with an Erbium-Doped Fiber Amplifier (EDFA) and a Fiber-Optic Fabry–Perot Interferometer

Analytical Letters
An all-optical double-pass quartz enhanced photoacoustic spectroscopy (QEPAS) sensor for the detection of acetylene (C2H2) at part-per-billion (ppb) levels was developed and experimentally validated.
Cheng Lin, Xuelian Zhang, Xueyang Yan, Yan Cai, Wenjie Li   +4 more
semanticscholar   +1 more source

QEPAS sensor for in-situ measurement of CO2 and its isotopic fingerprint

Optica Sensing Congress 2024 (AIS, LACSEA, Sensors, QSM)
We present the design and first results of a Photoacoustic Spectroscopy sensor to measure in-situ CO2 concentration and the δ13C isotopic fingerprint.
Marta Ruiz-Llata, Yuliy M. Sanoyan, Lucía Hidalgo-Arteaga   +2 more
semanticscholar   +1 more source