Method for real time monitoring exposure amount in holographic grating manufacture

Abstract

The invention relates to a method for the real-time exposure monitoring during the preparation of a holographic grating. The method belongs to the technical field of spectrum and relates to a method for the real-time exposure monitoring during the preparation of the holographic grating. The technical problem to be solved is to provide the method for the real-time exposure monitoring during the preparation of the holographic grating. The technical proposal comprises the following steps: 1, providing with a set of holographic grating exposure device; 2, providing with a set of real-time monitoring device capable of precisely controlling the exposure of the holographic grating; 3, preparing a latent image grating and carrying out the real-time monitoring of the exposure; and 4, determining an exposure cutoff point. The method which introduces the real-time monitoring technology into the exposure process so as to determine the exposure cutoff point is a simple and effective means. The real-time exposure monitoring device can be used for the rapid and precise control on the exposure of the holographic grating, thereby further correctly determining the best exposure cutoff point, and providing scientific theoretic instruction and experiment basis for the holographic grating exposure technology.

Description

technical field [0001] The invention belongs to the field of spectrum technology and relates to a method for real-time monitoring of exposure in the manufacture of holographic gratings. Background technique [0002] In the holographic grating manufacturing process, the exposure amount is one of the important process parameters that need to be controlled. Underexposure or overexposure cannot obtain an ideal grating groove shape. The traditional method is to use a fixed exposure time, make a large number of samples, repeatedly correct the exposure amount, summarize the best process parameters, and then use the experience value for subsequent exposure. Because there are many process conditions that affect the quality of holographic gratings, this research method requires a large amount of experimental work and a long cycle, and ultimately no good quality holographic gratings can be obtained. The closest prior art with the present invention is that Chinese Patent No. CN1450426 ...

AI Technical Summary

Problems solved by technology

The method is based on the latent image self-diffraction of the holographic interferometry system I r2 and I l1 A collimating lens is added in the direction of propagation, and a photomultiplier tube is placed on the focal plane to detect the energy of the concentrated light, and then the signal is transmitted to the recorder to realize real-time self-monitoring of the latent image. In this method, The recording light is irradiated on the latent image grating as monitoring light, and the photomultiplier tube is used to receive the diffracted light for real-time monitoring. Since the diffracted light energy of the latent image grating is very weak, there is stray light originating from the recording light in the optical path, and this part of the stray light energy The energy of the diffracted light of the latent image grating is stronger than that of the latent image grating, which causes the background light to be too strong, so it is very difficult for the photomultiplier tube to receive the diffracted light of the latent image grating

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