Design method of variable optical path length multi-pass cell

Zhang, Zhenxi; Zhou, Hongming; Chen, Xufei; Bi, Yong

doi:10.1007/s00340-020-07565-7

Cited by 9 publications

(2 citation statements)

References 24 publications

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“…The gain coefficient of acoustic amplification changes with the optimization of reflection times, which is based on the change in the total length of the light-gas interaction. Sennaroglu and Fujimoto put forward the re-entry condition as follows , N | θ | = 2 M π where M is the number of tracks. The reflection times N and integer M increase in steps 2 and 1, respectively.…”

Section: Principle and Design Application Of Photoacoustic Excitation...mentioning

confidence: 99%

“…The sensitivity of the photoacoustic sensing system is principally determined by the effective absorption path, which mainly depends on the reflection cavity length d and the reflection times N. The gain coefficient of acoustic amplification changes with the optimization of reflection times, which is based on the change in the total length of the light-gas interaction. Sennaroglu and Fujimoto put forward the re-entry condition as follows 39,40…”

Section: ■ Principle and Design Application Of Photoacoustic Excitati...mentioning

confidence: 99%

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Ultrahigh Sensitive Trace Gas Sensing System with Dual Fiber-Optic Cantilever Multiplexing-Based Differential Photoacoustic Detection

Zhao,

Wang,

et al. 2024

Anal. Chem.

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An ultrahigh sensitive trace gas sensing system was presented with dual cantilever-based differential photoacoustic detection. By combining the double enhancement of multipass absorption and optical differential detection, the gas detection sensitivity was significantly improved. The dualchannel synchronous photoacoustic detection was realized by fiber-optic Fabry−Perot interference spectrum multiplexing. The photoacoustic signals detected by two fiber-optic cantilever microphones installed in a differential photoacoustic cell (DPAC) were out of phase, while the detected gas flow noises were in phase. The optical differential detection method achieved both highly sensitive optical interference measurement and differential noise suppression. In the multipass configuration, the interaction path between excitation light and target gas achieved 4.1 m, which improved the photoacoustic signal by an order of magnitude compared with a single reflection. The maximum gas flow allowed by the system based on the DPAC was 250 sccm, which realized the dynamic monitoring of H 2 S in the SF 6 background. The detection limit for H 2 S in SF 6 background was 5.1 ppb, which corresponds to the normalized noise equivalent absorption coefficient of 9 × 10 −10 cm −1 W Hz −1/2 .

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