Opt Lett. 2018 Oct 15;43(20):5038-5041. doi: 10.1364/OL.43.005038.
An all-optical photoacoustic spectroscopy based on lock-in white-light interferometry is proposed for trace gas detection. The cavity length of the fiber-optic Fabry-Perot cantilever microphone is demodulated by a high-speed white-light interferometer, whose spectral sampling is synchronously triggered by a phased locked signal. To improve the signal-to-noise ratio, the demodulated digital photoacoustic signal is further processed by a specially designed virtual lock-in amplifier. The designed photoacoustic spectrometer has been tested for trace acetylene (CH) detection in the near-infrared region. The normalized noise equivalent absorption coefficient for CH is achieved to be 1.1×10 cm W Hz.
提出了一种基于锁相白光干涉的全光学光声光谱法用于痕量气体检测。光纤法布里-珀罗悬臂微音器的腔长由高速白光干涉仪解调，其光谱采样由相锁信号同步触发。为了提高信噪比，解调的数字光声信号进一步由专门设计的虚拟锁相放大器处理。设计的光声光谱仪已用于近红外区痕量乙炔（CH）的检测。实现了归一化噪声等效吸收系数为 1.1×10 cm W Hz 的 CH。
