Laser speckle suppression element and suppression method

Abstract

The present application discloses a laser speckle suppressing element and a suppressing method, which are used to improve the efficiency of speckle suppression and enhance the effect of speckle suppression. The element adopts a light-transmitting material; it includes an array composed of a plurality of light-transmitting regions; wherein, the lateral size of the light-transmitting regions is smaller than the spatial resolution of the human eye, and the difference in the longitudinal dimensions of adjacent light-transmitting regions makes the transmission of adjacent light-transmitting regions The optical path difference of the laser beams in the light area is not less than the coherence length of the laser beams. In this way, the time coherence between adjacent sub-laser beams can be destroyed, and the spatial coherence of the laser can be destroyed, so that adjacent sub-laser beams become The non-correlated light is obtained, so that the spatial superposition of multiple independent speckles can be realized within the resolution of the human eye, and the effective suppression of speckle can be realized.

Description

technical field [0001] The invention relates to the field of optical technology, in particular to a laser speckle suppressing element and a suppressing method. Background technique [0002] Due to its advantages of high brightness, pure color and long life, laser light source has gradually replaced xenon light source as the light source of projection system. Due to the strong temporal and spatial coherence of the laser, when the laser is irradiated on the surface of a rough object, it will produce a granular light intensity distribution with bright and dark distribution, which is called speckle. The existence of speckle seriously affects the quality of the projected picture, thereby affecting the viewing effect. For example, if such speckle exists in the projection screen of a laser movie machine, it will seriously affect the quality of the movie screen. [0003] At present, the commonly used methods of speckle suppression are vibrating screens or rotating scatterers, both ...

AI Technical Summary

Problems solved by technology

The existence of speckle seriously affects the quality of the projected picture, thus affecting the viewing effect. For example, if there is such speckle in the projection screen of the laser movie machine, it will seriously affect the quality of the movie screen

[0003] At present, the commonly used methods of speckle suppression are vibrating screens or rotating scatterers, both of which achieve speckle suppression by superimposing different speckle images over time within the integration time of the human eye. Vibrating screens are used for speckle suppression When using mechanical motors and other driving devices, it will generate noise, deform the screen and shorten its service life, and cause low system stability.

However, when a rotating diffuser (or a rotating optical flat plate) is used for speckle suppression, the stability of the suppression system is low and the speckle suppression efficiency is not high

Images