Patent ID: 6914715
Filing Date: 2005-07-05
Classification: B82Y,G02B

Abstract:
1. An optical element comprising a two-dimensional photonic crystal structure having structurally periodic repetition in directions of Y and Z axes perpendicular to each other, wherein: two opposite surfaces of said photonic crystal structure which are perpendicular to the Z-axis direction and parallel to the Y-axis direction are used as a light input surface and a light output surface respectively; a direction of movement of light rays incident onto said light input surface is parallel to a plane containing said Y and Z axes and inclined at a predetermined inclination angle to the Z-axis direction, wave number vectors belonging to photonic bands according to the direction and frequency of input light are present in said two-dimensional photonic crystal structure; and at least one of said wave number vectors forms an angle of not larger than 30° with respect to a line normal to said light input surface.