Patent ID: 9477018
Filing Date: 2016-10-25
CPC Classification: G01B,G02B,G03H

Claim Text:
1. A diffractive optical element, comprising: a transparent substrate having a concave and convex pattern comprising concave portions and convex portions such that the concave and convex pattern diffracts incident light in two dimensions and generates diffracted light having a maximum diffraction angle with reference to an optical axis of an incident light in an angle range of 7.5° or greater, and diffraction efficiency of 5% or less in a zero-order diffracted light beam, wherein the concave and convex pattern has a distribution of the convex portions such that the convex portions have different shapes having different lengths measured in an X axis direction and a Y axis direction with respect to a Z axis direction representing a height direction of the convex and concave portions, and the lengths measured in the X axis and the Y axis are distributed in different frequencies within a range of λ/8 to 6λ where λ represents a wavelength of the incident light.