Abstract: The effective suppression of laser noise is the basis of precision measurement research, and especially, it is required for modern quantum information science to reach shot noise limit in light field. A noise suppression system combining photoelectric negative feedback and mode cleaner is studied in this work. Based on the sideband model and Langevin equation, the noise spectrum of the output light field of the noise suppression system is analyzed, and the effects of the transmittance, feedback gain of the photoelectric negative feedback loop and the cavity linewidth of the optical mode cleaner on the noise suppression level are discussed. The results show that the system can not only effectively suppress the intensity noise at high frequency to reach the limit of shot noise, but also reduce the intensity noise at specific frequencies. In addition, the introduction of bandpass filter can further extend the level and bandwidth of noise suppression. The results provide direct reference and necessary basis for experimental research.

Key words: quantum optics, intensity noise suppression, photoelectric negative feedback, mode cleaner