Optical diffraction element-based laser speckle suppressing method

Abstract

The invention relates to an optical diffraction element-based laser speckle suppressing method. According to the implementation system of the method, a laser beam emitted by a laser is subjected to beam expansion, shaping and calibration by a modulation lens assembly; and the normal incidence of the processed laser beam into the plane of a binary optical diffractive element is realized; the binary optical diffractive element can be mounted on a horizontal guide rail in a horizontally movable manner, an included angle being formed between the binary optical diffractive element and a horizontal plane; the movement velocity and the included angle of the binary optical diffractive element are calculated according to the theoretical derivation of a mathematical model; and the binary optical diffraction element is controlled to move according to the set movement velocity and the included angle. The optical diffraction element-based laser speckle suppressing method provided by the invention has the advantages of good speckle suppression effect, simple structure, easiness in realization, good system versatility, good robustness and low cost.

Description

technical field [0001] The invention belongs to the field of laser display projection, and in particular relates to a speckle suppression method. Background technique [0002] Laser speckle is a layer of granular structure observed on the surface of rough objects when a diffuser is illuminated with laser light. The essence of speckle is a random coherent superposition. Speckle is noise in imaging and information images, and usually seriously affects the quality of images and information. Therefore, speckle suppression is required in laser systems, especially laser display projection systems. [0003] Due to the importance of speckle suppression, predecessors have carried out a lot of theoretical research. The theoretical methods of speckle suppression in optical projection that have been proposed can be roughly divided into 8 types: 1. Introduce polarization diversity; 2. Introduce a moving screen ; 3. Introduce a specially designed screen to minimize the speckle; 4. For e...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the shortcomings of the existing speckle suppression technology and system structure, high experimental precision requirements, difficult implementation, poor system fault tolerance, robustness, versatility, and insufficient speckle suppression effect, the present invention provides a speckle suppression Laser speckle suppression method based on optical diffraction element with good effect, simple structure, easy implementation, system versatility, good robustness and low cost

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