为了对双声光调制器(AOM)的频差进行高精度检测,设计了一种基于频谱校正的外差干涉检测方法及实验系统。通过测量外差干涉信号的频率,获得双AOM的实际频差大小。信号频率的精确提取采用加Hanning窗的比值频谱校正法。仿真分析了利用不同信噪比信号对频差的检测精度与采样点数的关系,并设计搭建实验系统对一组双AOM的频差进行检测,结果表明,所采用的算法对双AOM频差的检测精度优于2 Hz。该检测方法可以为高精度外差测量系统的误差分析提供有效参考。 In order to detect the AOM frequency difference with high accuracy, a spectrum-based heterodyne interference detection method and an experimental system are designed. By measuring the frequency of the heterodyne interference signal, the actual amplitude of the double AOM is obtained. Accurate extraction of the signal frequency using the Canadian Hanning window ratio spectrum correction method. The relationship between the detection accuracy of frequency difference and the number of sampling points by using different signal to noise ratio signals is simulated and analyzed. The experimental system is designed to detect the frequency offset of a group of AOMs. The experimental results show that the proposed algorithm has good performance on the AOM frequency difference Detection accuracy better than 2 Hz. The detection method can provide an effective reference for error analysis of high accuracy heterodyne measurement system.