Three-dimensional grating

The utility model discloses a three-dimensional grating, wherein the surface microstructure of the three-dimensional grating is in the mode of a U-shaped groove, wherein the width of the U-shaped groove refers to the linear distance of wave trough sections formed between surfaces of two adjacent three-dimensional gratings, and the ratio of the width of the U-shaped groove to the grating pitch is 0-0.5; the curvature radius of the U-shaped groove refers to the radius of the wave trough section formed between the surfaces of two adjacent three-dimensional gratings, and the ratio of the curvature radius of the U-shaped groove to the curvature radius of a grating projection is 0-0.40. The three-dimensional grating disclosed by the utility model adopts the U-shaped groove surface microstructure, thereby enabling the structure of a grating material to be diversified, and improving the low temperature impact resistance of products on the basis of not changing the optical performance thereof; selection of materials i