Diffractive optical element

Abstract

The invention relates to the technical field of optical elements, in particular to a diffractive optical element. In order to solve the problems of inconsistency between sub-beam power and expected power when a diffractive optical element that is high in manufacture error is used for beam splitting of light, the invention provides the diffractive optical element which comprises phase distribution A and phase distribution B. The phase distribution A conforms to 0 / cX<pi> binary distribution, where c is in a numerical range of 0.5-1.5. The phase distribution B compensates with the phase distribution A, that is, the sub beam power outputted when a laser passes through the phase distribution B compensates with the sub beam power outputted when a laser passes through the phase distribution A. The invention achieves compensation of the power between sub beams by means of combining the phase distribution A with the phase distribution B, so that the sub beam power is consistent with the expected power.

Description

technical field [0001] The invention relates to the technical field of designing optical elements, in particular to a diffractive optical element. Background technique [0002] Diffractive optical elements can be used in many fields, such as structured light for human-computer interaction, gesture recognition, robot vision, laser material processing (such as porous simultaneous processing, high-speed laser texturing), optical communication, optical image processing, microelectronics, Microscope, fiber coupling, etc. [0003] When the diffractive optical element is used to split the laser beam, it can convert a laser beam into multiple beams (usually called sub-beams). At this time, the diffractive optical element is usually called diffractive beam splitting element, array generator, splitting beam Beam grating, or simply grating, beam splitting element, etc. [0004] US Patent No. US2013120841 discloses an Optical pattern projector. The optical device in this patent includ...

AI Technical Summary

Problems solved by technology

However, when the precision of the manufacturing equipment is low, that is, when the size of the microstructure of the diffractive optical element is smaller than the resolution of the manufacturing machine, the manufacturing error is large, and when the obtained diffractive optical element splits the light, the power of the sub-beams is inconsistent with the expected power. A common error is that in the output matrix sub-beams, the power of the 2 beams along one diagonal is greater than the power of the 2 beams along the other diagonal (such as figure 1 shown), this result strongly affects the use of diffractive optical elements

[0006] Because high-precision equipment is expensive and cannot be widely used, most manufacturers of diffractive optical elements still use relatively low-precision manufacturing equipment. Therefore, the diffractive optical elements they produce have the above-mentioned problems

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