Patent ID: 8730565
Filing Date: 2014-05-20
Classification: G02F

Abstract:
1. A device for irradiating an electromagnetic wave having a target frequency in a range of 0.1 THz to 30 THz to an outside of a non-linear optical crystal: said device comprising a main body comprising a non-linear optical crystal and a sub wavelength grating structure formed on a surface of said main body, said sub wavelength grating structure comprising column shaped bodies regularly arranged on said surface of said main body; wherein each of said column shaped bodies comprises a constant width part having a constant width and provided in a side of an end of said column shaped body, said column shaped body further comprising a base part provided from said surface of said main body toward said constant width part; and wherein a surface of said base part has a shape of an arc having a center of curvature in an outside of said base part, viewed in a cross section of said column shaped body cut along a direction in which said column shaped bodies are arranged.