针对扫描干涉光刻机干涉图形相位锁定需求,提出并设计了干涉图形相位锁定系统。该系统采用零差相位干涉仪实现干涉图形相位漂移的高速高精测量,采用声光调制器以高速高精移频的方式进行干涉图形相位调制,并通过闭环反馈控制实现相位锁定。实验结果显示:系统闭环控制可实现±1/25个干涉图形周期的锁定精度,系统具有良好的相位锁定性能。该系统具有光路短、易于装调、激光利用率高等优点,未来用于扫描干涉光刻机更具优势。 Aiming at the requirement of interferometric pattern phase locking for scanning interference lithography, an interferometric pattern phase locking system is proposed and designed. The system uses homodyne phase interferometer to realize high-speed and high-precision measurement of phase shift of interferogram. The acousto-optic modulator is used to carry out phase modulation of interferogram with high-speed and high-precision frequency shift, and the phase lock is achieved by closed-loop feedback control. The experimental results show that the closed-loop control of the system can achieve the locking accuracy of ± 1/25 interference pattern cycles and the system has good phase locking performance. The system has the advantages of short optical path, easy installation and adjustment, high laser utilization rate and the like, and has the advantage of being used for scanning interference lithography in the future.