高灵敏高分辨钛宝石激光光声光谱仪--光学长程+声学共振

分析了影响光声信号大小的多种因素，特别是光声池的大小对光声信号的影响。使用适当尺寸的圆柱形光声池并使其工作在一阶径向共振状态，结合光学长程技术，显著提高了光声信号的信噪比。用钛宝石激光器作光源，光声光谱仪的探测灵敏度达８．５×１０－ ９ ｃｍ － １（１ｖ１ 信噪比），并测出砷烷分子振动量子数为６的高分辨泛频谱。

A Highly Sensitive Doppler Limited Photoacoustic Overtone Spectrometer with a Ti:sapphire Ring Laser-Optical Multipass and Acoustic Resonance

The factors, especially the photoacoustic cell′s size, which have effects on the amplitude of the photoacoustic signal, are analysized. When a multipass cylindrical cell with optimal dimensions is operated in the first-order radial resonance mode, the signal-to-noise ratio of photoacoustic signal can be greatly improved. Using a Ti:sapphire ring laser as the light source, a laser photoacoustic spectrometer reaching a sensitivity of 8.5×10-9 cm-1 (SNR=1:1) is realized; then the sixth stretching overtone spectrum of AsH3 was first recorded with this instrument.