光声光谱技术用于检测低浓度乙炔气体具有灵敏度高、连续和快速实时在线测量的特点。采用近红外可调谐掺铒光纤激光器(TEDFL)串接大功率掺铒光纤放大器(EDFA)作光源，采用一阶纵向共振式双程吸收光声池，并运用波长调制和二次谐波检测技术，研制出一种新的高灵敏度微量气体近红外光声光谱分析仪。在常温常压下对低浓度乙炔气体的实验测量结果表明，该系统的极限检测灵敏度达到1.3×10-9，其线性响应相关度达到0.99957，能够满足工业、环境监测和电力系统等对乙炔检测和分析的需要。

The technology of photoacoustic spectrum has features of high sensitivity, continuous and fast in situ measurement in detecting acetylene in low concentration. A new wavelength modulated photoacoustic spectrometer based on a near-infrared tunable erbium doped fiber laser (TEDFL) and a high power erbium doped fiber amplifier (EDFA) is developed. This system is demonstrated with low concentration acetylene measurement at the 1530.37 nm transition line, by incorporation of a first-longitudinal resonant photoacoustic cell with double absorption optical path and lock-in harmonic detection technique, yielding a detection limit of 1.3×10-9 at room temperature and atmospheric pressure and this can meet the demands of acetylene detection and analysis in industry, environment monitoring and power system.