Holographic grating exposure method adopting heterodyne interference fringe locking control

Abstract

The invention provides a holographic grating exposure method adopting heterodyne interference fringe locking control, belonging to the field of spectrum techniques. The existing holographic grating exposure method realized by adopting a linear array CCD (Charge Coupled Device) in the prior art has the problem that high-frequency fringe jitter inhibition effect is poor due to a reason that the response speed of the linear array CCD is slow. A set of holographic grating exposure device and a set of heterodyne interference fringe locking control device are equipped. Interference fringes are locked in real time and are placed on a grating substrate for exposure. The method provided by the invention has the advantages that the interference fringes can be locked at a certain fixed value relative to the phase of the grating substrate during exposure of a holographic grating; since the control bandwidth is larger, the high-frequency fringe jitter can be better inhibited, the contrast of the groove profile of the holographic grating is guaranteed and the manufacturing process level of the holographic grating is improved.

Description

technical field [0001] The invention relates to the field of spectrum technology, in particular to a holographic grating exposure method using heterodyne interference fringe locking control. Background technique [0002] The holographic grating is an important optical component, and the exposure process of the holographic grating is one of the most important process links in the holographic grating manufacturing process. Existing holographic grating exposure devices, such as figure 1 As shown, it includes a source laser 1 , a first beam splitter 4 , a second plane mirror 5 , a third plane mirror 6 , a first beam expander 15 , a second beam expander 16 , and an interference field 17 . The light source laser passes through the first beam splitter 4, and the two light beams become the first recording light 7 and the second recording light 8 after passing through the second plane mirror 5 and the third plane mirror 6, and the two beams respectively pass through the second plane...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem in the prior art of using a linear array CCD to realize the holographic grating exposure method that the response speed of the linear array CCD is relatively slow, resulting in a poor suppression effect on the fringe jitter of a higher frequency, a method using a heterodyne method is provided. Holographic grating exposure method with interference fringe locking control

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