Patent ID: 8746890
Filing Date: 2014-06-10
Classification: G02B,G03B,H04N

Abstract:
1. A polarization beam splitting element configured to split an entering beam in a visible wavelength range according to polarization directions, the element comprising: a one-dimensional grating structure having a grating period smaller than a wavelength of the entering beam and including a grating portion formed of a metal; and two light-transmissive members each having a refractive index higher than that of air and each being formed of a light-transmissive material, wherein the one-dimensional grating structure is disposed between the two light-transmissive members, wherein the grating period of the one-dimensional grating structure is 120 nm or less, a thickness of the one-dimensional grating structure is 100 nm or less and an inter-grating portion of the one-dimensional grating structure is formed as a vacuum space or formed of air or a dielectric material, and wherein the grating period Λ [nm], a filling factor FF that is a ratio w/Λ of a width w [nm] of the grating portion to the grating period, a refractive index n