All-Optical Cantilever-Enhanced Photoacoustic Spectroscopy in the Open Environment

作者：Wei Wei^*; Zhu Yong; Lin Cheng; Tian Li; Xu Zhuwen; Nong Jinpeng

来源：International Journal of Thermophysics, 2015, 36(5-6): 1116-1122.

DOI：10.1007/s10765-015-1902-7

• Cantilever
• Optical fiber Fabry-Perot
• Photoacoustic spectroscopy
• Trace gas detection

A novel all-optical cantilever-enhanced photoacoustic spectroscopy technique for trace gas detection in the open environment is proposed. A cantilever is set off-beam to "listen to" the photoacoustic signal, and an improved quadrature-point stabilization Fabry-Perot demodulation unit is used to pick up the vibration signal of the acoustic transducer instead of a complicated Michelson interferometer. The structure parameters of the cantilever are optimized to make the sensing system work more stably and reliably using a finite element method, which is then fabricated by surface micro-machining technology. Finally, related experiments are carried out to detect the absorption of water vapor at one atmosphere in the open environment. It was found that the normalized noise-equivalent absorption coefficient obtained by a traditional Fabry-Perot demodulation unit is , while that by a quadrature- point stabilization Fabry-Perot demodulation unit is , which indicates that the sensitivity is increased by a factor of 3.1 using improved cantilever-enhanced photoacoustic spectroscopy.

• 出版日期2015-6
• 单位重庆大学