Study of characteristic of fringe locking system used to holographic exposure

In order to study the relationship between the contrast of holographic grating and the root mean square(RMS) value of interferential fringe moving,a fringe locking system constituted by Moire fringe theory and charge coupled device camera is used to shot holographic grating.The value of moving Moire fringe is real-time gathered by CCD.It has been discovered that the fringe moving is composed by slowly excursion and vibration of 3.1Hz.And the RMS value of fringe moving is correlated with the contrast of holographic grating.Academic reference is put forward for testing weather the quality of holographic grating is eligible or not.The results showed that the RMS value should be less than 0.05λ to improve the quality of grating.And the fringe locking system can choke back the slowly fringe moving.