Abstract: An adaptive algorithm for extracting weak signal based on the theory of stochastic resonance(SR) was proposed. It was implemented by investigating the self correlation of the outputs of the bistable system(with different μ). The results show that the self-correlation will reach maximum when a sudden change of output occurs, and hence prove that SRis sensitive sharply to the change of the parameters μ, and also provide one novel method to express the outputs which hasn't been solved till now. The adaptive algorithm was also applied to analyze the weak Laser-Raman spectrum of a CCl₄ sample(liquid in capillary) which was measured with SPEX-1403 Laser-Raman spectrometer from²50 cm^-1 to 418 cm^-1 on₅ mW(output power of laser). The spectrum was analyzed with the adaptive algorithm by varying the data to (-413, 350) and declining μ from²0 with step 001. The results obtained show that the adaptive algorithm was able to detect the weak signal automatically and correctly.

Key words: Stochastic resonance, Weak signal detection, Adaptive algorithm, Raman spectrum