可调谐半导体激光吸收光谱(TDLAS) 技术是近年来发展起来的一种新型光纤气体传感器技术，目前这种技术主要有3类方法：谐波幅度法，一、二次谐波幅度比值法，差分法。针对这3类方法的特点与不足进行综合分析，并在此基础上提出了谐波峰平比法（PAPR）。采用该方法设计的光纤甲烷气体传感器性能稳定，样机经相关机构检测后表明，传感器响应时间为10 s，在0～5×10-3的量程内，检测精度达满量程的5%，灵敏度为2×10-5。

Tunable diode laser absorption spectroscopy technology is a developing technollgy on new optical gas sensor in recent years, currently there are three research methods: harmonic amplitude method, first to second harmonic signal amplitude ratio method and difference method. The harmonic peak to average power ratio (PAPR) is proposed on the base of comprehensive analyzing on the features and disadvantages of those three methods. The performance of optical methane gas sensor with new method is stable, and the detection results of the prototype are as follows: response time of sensor is 10 s, in the range of 0～5×10-3 the detection precision and sensitivity are 5% of full scale and 2×10-5, respectively.