Enhanced laser gas concentration detection method based on stochastic resonance

The invention provides an enhanced laser gas concentration detection method based on stochastic resonance. Compared with a traditional weak periodic signal detection method, the enhanced laser gas concentration detection method based on stochastic resonance can convert part of noise energy into signal energy under the resonance condition, so that noise is restrained, signals are amplified, and the signal-to-noise ratio of the signals is increased. Firstly, numerical simulation calculation is carried out on the method, and optimal resonance parameters of the SR method are found; in a stochastic resonance state, a peak value (CH4 concentration is 20 ppm) of a laser second harmonic signal (2f) is effectively amplified to 0.0863 V, which is 3.8 (a larger multiple can be amplified) times of an average peak value (0.0231 V) of a 2f signal for 4000 times. The standard and the signal-to-noise ratio are correspondingly improved by two times, and the linear spectrum response of the peak value of the 2f signal to the pe