1. Acousto-Optic Q-Switched Fiber Laser-Based Intra-Cavity Photoacoustic Spectroscopy for Trace Gas Detection.
- Author
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Zhang, Qinduan, Chang, Jun, Wang, Qiang, Wang, Zongliang, Wang, Fupeng, and Qin, Zengguang
- Subjects
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ACOUSTOOPTICS , *Q-switched lasers , *FIBER lasers , *GAS detectors , *PHOTOACOUSTIC spectroscopy , *TRACE gases - Abstract
We proposed a new method for gas detection in photoacoustic spectroscopy based on acousto-optic Q-switched fiber laser by merging a transmission PAS cell (resonant frequency f 0 = 5.3 kHz) inside the fiber laser cavity. The Q-switching was achieved by an acousto-optic modulator, achieving a peak pulse power of ~679 mW in the case of the acousto-optic modulation signal with an optimized duty ratio of 10%. We used a custom-made fiber Bragg grating with a central wavelength of 1530.37 nm (the absorption peak of C2H2) to select the laser wavelength. The system achieved a linear response (R2 = 0.9941) in a concentration range from 400 to 7000 ppmv, and the minimum detection limit compared to that of a conventional intensity modulation system was enhanced by 94.2 times. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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