Patent ID: 6999155
Filing Date: 2006-02-14
Classification: G02B,G02F,H04N

Abstract:
1. A polarization rotator for rotating a polarization direction of linearly polarized input light by an angle γ different from 90°, comprising a first input alignment surface, a second output alignment surface, and a layer of liquid crystal material having a liquid crystal director and being disposed between said first alignment surface and said second alignment surface, said rotator having a mode in which a 90° twist of said liquid crystal director is induced across said layer, the layer having a retardation substantially given by: where λ is a wavelength of light, Δn is a birefringence of said liquid crystal material, d is a thickness of said layer, and θ is an angle between said polarization direction of said input light and an alignment direction of said first alignment surface, and where 175°≦|γ|≦180°.