Structured light projection diffractive optical device based on superstructure surface

Abstract

The invention relates to a structured light projection diffractive optical device based on a superstructure surface, and belongs to the technical field of depth perception and optical imaging. The device provided by the invention consists of a substrate and a plurality of sub-wavelength optical antenna arrays arranged in a periodic form on the surface of the substrate, wherein the sub-wavelength optical antenna arrays are one-dimensional arrays or two-dimensional arrays; when the sub-wavelength optical antenna arrays are one-dimensional arrays, the respective optical antennas are wire grids arranged in the direction of a column and having rectangular or trapezoidal cross sections; when the sub-wavelength optical antenna arrays are two-dimensional arrays, the respective optical antennas arecylinders forming planes in the direction of a column and a row and having circular or arbitrary regular polygon shaped cross sections; in each of the sub-wavelength optical antenna arrays, the diameter of each optical antenna is 1 / 20 to 1 / 2 of the operating wavelength, the heights of the respective optical antennas are all equal and in the sub-wavelength range, and the center distances of the adjacent two optical antennas are both equal and not more than half of the operating wavelength. The device provided by the invention can realize structured light projection having a large diffraction angle, high diffraction efficiency, high uniformity and insensitive incident light polarization.

Description

technical field [0001] The invention can be applied to the fields of depth perception, optical imaging and the like, and in particular relates to a metasurface-based structured light projection diffraction optical device. Background technique [0002] Structured light refers to a specific coded laser dot matrix or laser speckle. Project the structured light onto the measured object, use the camera to capture the reflected pattern of the measured object, and compare the shape and size of the received light point with the projected light point to obtain the depth information of each point of the measured object, and then restore The three-dimensional shape of an object. The three-dimensional stereo vision that can be realized by structured light can be widely used in many fields such as industrial inspection, life security, unmanned driving, etc., and has received more and more attention. At present, the products based on structured light include the face recognition module ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem of small diffraction angle and low efficiency of structured light in the prior art, the present invention provides a method to achieve large diffraction angle, high efficiency and high uniformity by designing the geometric size and arrangement period of the sub-wavelength nano-cylindrical antenna. Structured light projection device

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