采用声光频移器反馈控制实现激光强度稳定

本文基于声光频移器，采用光电反馈方式实现了激光强度的稳定控制。根据声光频移器的布拉格衍射对激光强度的调节作用，以光电反馈得到的反馈电信号控制驱动声光频移器的射频功率大小，进而对声光频移器的输出激光强度进行稳定，激光在47 kHz以下的低频噪声实现最大抑制比为15 dB。实验结果基本满足了所要求的激光稳定度。此外还分析了整个回路的响应特性，测试了除反馈电路之外其他部分的相移特性。

Laser intensity stabilization by using of opto-electronic feedback control based on an acousto-optical frequency-shifting system

The laser intensity could be stabilized by using opto-electrical feedback based on the acoustic opti- cal shifted modulator outside the laser. Due to the Bragg diffraction effect of an acousto-optical modulator （AOM） on controlling of the laser intensity, the feedback electrical signal from a portion of laser was applied to control the driving power of the AOM realizing the stabilization of laser intensity. The experiment results show that the laser intensity noise under the frequency of 47 kHz can be reduced by 15 dB. In addition, the time response in whole feedback loop is analyzed, and the delay phase curve beside the feedback circuit in the loop is also measured.