Li Chenxi, Zhang Yajie, Guo Min, Qi Hongchao, Zhao Xinyu, Chen Ke
School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China.
Zhejiang Engineering Research Center of MEMS, Shaoxing University, Shaoxing, Zhejiang 312000, China.
Anal Chem. 2024 Mar 19;96(11):4562-4569. doi: 10.1021/acs.analchem.3c05396. Epub 2024 Mar 7.
Aiming at the problem of the fiber-optic photoacoustic (PA) sensor being easily disturbed by external vibration and noise, a differential cantilever enhanced fiber-optic PA sensor is proposed for diffusion gas detection. The sensor comprises two PA tubes with the same structure and a pair of differential interferometric cantilevers. The two PA tubes are symmetrically distributed. The laser is incident on the PA tube as the signal channel to excite the PA pressure wave. Another tube without incident laser is used as the reference channel to suppress external disturbance. The external interference signals and PA signals superimposed with disturbance are detected by the differential cantilevers from the two channels. The signals are simultaneously restored by a single white-light interferometry demodulator, which multiplexed the spectral frequency domain of the superimposed interference spectrum. The experimental results show that the suppression effect of the differential cantilever enhanced PA sensor on ambient noise is improved by 80%, compared to the traditional single-cantilever sensor. The external cofrequency disturbance is suppressed by 20.9 dB. The minimum detection limit to acetylene (CH) downs to about 60 ppb with an integration time of 100 s. The sensor has excellent antivibration and electromagnetic interference ability.
针对光纤光声（PA）传感器易受外部振动和噪声干扰的问题，提出了一种用于扩散气体检测的差分悬臂梁增强型光纤PA传感器。该传感器包括两个结构相同的PA管和一对差分干涉悬臂梁。两个PA管对称分布。激光入射到作为信号通道的PA管上，以激发PA压力波。另一个没有激光入射的管用作参考通道，以抑制外部干扰。差分悬臂梁从两个通道检测外部干扰信号和叠加有干扰的PA信号。信号由单个白光干涉解调器同时恢复，该解调器对叠加干涉光谱的频谱频域进行复用。实验结果表明，与传统的单悬臂梁传感器相比，差分悬臂梁增强型PA传感器对环境噪声的抑制效果提高了80%。外部同频干扰被抑制了20.9 dB。在积分时间为100 s时，对乙炔（CH）的最低检测限降至约60 ppb。该传感器具有出色的抗振动和电磁干扰能力。
