Binary grating array and method for realizing symmetric dot matrix characteristic graph

Abstract

The invention discloses a binary grating array and method for realizing a symmetric dot matrix characteristic pattern, and the method comprises the steps: obtaining the period of a grating corresponding to a pair of symmetric points according to the wavelength of incident light and the divergence angle of the pair of symmetric points of the symmetric dot matrix characteristic pattern, and then according to the spatial position direction of the pair of light spots, designing the etching direction of the corresponding grating unit, and finally obtaining the etching depth of the grating according to the beam splitting condition of the grating corresponding to the pair of symmetric points. Each grating structure is designed in this way, and the grating structures are combined to form a microstructure unit of the final diffraction grating element. The binary grating array is simple in structure, the preparation method is simple and convenient in steps, and the binary grating array has the advantages of high operability, high reliability, high energy utilization rate, high replicability, weak diffracted light and the like, is wide in application range, and is suitable for realizing all symmetric dot matrix characteristic patterns.

Description

technical field [0001] The invention relates to the technical field of laser beam conversion, in particular to a binary grating array and a method thereof for realizing symmetrical lattice characteristic patterns. Background technique [0002] At present, in outdoor laser display industries such as laser medical treatment, laser scanning, and advertising, it is usually necessary to convert a single laser light source into a dot matrix of beams, and these dot matrixes are usually symmetrical patterns. With the development of these industries, the structural simplicity and reproducibility of beam transformation elements are increasingly required. Nowadays, for the generation of characteristic graphics of symmetrical lattices, there are mainly the following methods: [0003] The first one is based on the principle of diffractive optics, according to the desired lattice pattern, to obtain the phase information that the diffractive element needs to provide, so as to obtain the e...

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Problems solved by technology

[0005] However, the above two solutions have their own shortcomings. The first one has stray light, severe background light, and low energy utilization rate. In order to improve the light energy utilization rate, the only way to increase the etching order number, which will greatly increase the difficulty and uncertainty of processing, and is not conducive to the mass production of component replication; the second solution has a small scope of application, and can only achieve orthogonal and equally spaced dot matrix images, and cannot achieve other forms of bitmap

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