RESONANT OPTICAL CAVITY SYSTEM WITH OPTICAL FEEDBACK, SUITABLE FOR DETECTING TRACES OF GAS BY RAMAN SPECTROSCOPY

The invention relates to a method for analysing gas by Raman spectroscopy, and the method comprises steps: generating, with a laser source (100), a laser beam that scans a frequency range including a plurality of resonant modes of an optical cavity (180) including gases to be analysed; delivering the laser beam to the cavity; extracting, from the cavity, a feedback beam that is sent, amplitude- and phase-adjusted, to the source; during the scan of the frequency range, detecting light-intensity peaks (221-229) in the laser beam in the cavity, the phase of the feedback beam being adjusted to decrease asymmetries in the shapes of the peaks, the amplitude of the feedback beam being adjusted to decrease zero-intensity intervals between the peaks; and carrying out a spectral analysis on light inelastically scattered in the cavity, in order to determine the composition of the gases to be analysed. 本发明涉及一种通过拉曼光谱法进行气体分析的方法，该方法包括以下步骤：由激光源(100)生成激光束，该激光束扫描包括保持待分析气体的光学腔(180)的多个谐振模式的频率范围；将激光束送入腔；从腔中提取反馈光束，该反馈光束在相位和幅度上进行调节