The special optics and novel configuration make a feature of double-frequen-cy function amd insensitivity of Moire fringe modulation signal to gap between the main grat-ing and index grating.

• 该系统具有光学两倍频作用和大光栅副间隙下使用及间隙对莫尔条纹信号调制度不敏感等特点,并且整体结构分离式、小型化和轻型化,在各类精密测量装置和精密加工仪器中将得到越来越广泛的应用。