Polarizing element and optical system including polarizing element
US7589895B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 5, 2004 |
| Grant date | Sep 15, 2009 |
| Priority date | — |
| Expiry date | Jul 15, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A polarizing element usable for two wavelengths in a predetermined wavelength region and having a simple structure. The polarizing element has a two-layer structure in which a grid pattern of a constant period Λ having a triangular cross-section is formed on a substrate and a film with a refractive index higher than that of the substrate is deposited on the grid pattern. When first and second wavelengths λ1, λ2 satisfy λ1<λ2, Λ cos θ0<λ1 where θ0 is the angle of incidence on the grid surface. The grid period, the grid height, and the film thickness are determined so that with respect to the first wavelength λ1, the reflection efficiency of the TE-polarized zero-order diffracted light is a predetermined value or more and the transmission efficiency of the TM-polarized zero-order diffracted light is a predetermined value or more and so that with respect to the wavelength λ2, the transmission efficiency of the TE-polarized zero-order diffracted light is a predetermined value or more and the reflection efficiency of the TM-polarized zero-order diffracted light is a predetermined value or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.