Optical method for real time latent image self-moritoring in holographic raster manufacture

Abstract

The invention refers to a real-time latent-image self-monitoring method in the course of making a holographic grating. It uses arbitrary interference recording light beam of the light intensity acting on the grating as the real-time sub-image self-monotiring incident light beam, and when the ratio of the wavelength of the incident light beam and the period of the grating lambda / d<2 / 3, the grating has multiple diffraction levels, it real-time self-monitors the light beam outside the system collimated and photoelectricly multiplied in the transmission direction of self-diffractions Ir2 and Ir1 of arbitrary level sub-image, or real-timely self-monitors the autocollimating level returning according to the original route filtered, collimated and photoelectricaly multiplied.

Description

technical field [0001] The invention relates to an optical method for real-time latent image self-monitoring in the production of holographic gratings, in particular to an optical method for real-time latent image self-monitoring in the production of holographic gratings, which is widely used in the fields of spectroscopic instruments, measurement, optical information processing, and optical communication. Optical methods for monitoring. Background technique [0002] Diffraction gratings have a wide range of applications in many fields such as spectroscopic instruments, measurement, optical information processing and optical communication due to their unique wavefront segmentation and dispersion characteristics, and are often the core of the technology. At present, in scientific research and high-tech products, my country needs a large number of diffraction gratings, and the gratings with high quality and performance requirements basically rely on imports. There are many wa...

AI Technical Summary

Problems solved by technology

In order to obtain relatively strong diffracted light, a short-wavelength laser is usually used for monitoring; since the photoresist has a strong absorption of short-wavelength, the incident light for monitoring must be attenuated to a safe energy intensity; in order to detect such a weak signal, it is also necessary Add a chopper to modulate the signal, but the general diffraction efficiency can only reach 10 -6 ~10 -7 This makes it difficult to determine the direction of the incident light and diffracted light, the actual operation is very inconvenient, and it is more sensitive to the fluctuation of background light and laser output power

Therefore, the previous real-time monitoring method of latent image is complicated, expensive, difficult to operate, and the characteristics of the obtained monitoring curve are not obvious enough, and it is basically still in the stage of laboratory exploration, and it is not practical yet.

In addition, so far, no technology has been reported to greatly improve the groove quality and production efficiency of holographic gratings

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