Angular optical filtering element for angular filtering having controlled angular selectivity
US9810822B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 17, 2014 |
| Grant date | Nov 7, 2017 |
| Priority date | — |
| Expiry date | Nov 11, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2005/202
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
According to one aspect, the invention relates to an angular optical filtering element (Ei) optimized for angular filtering about a given operating angle of incidence (θi, 1) in a given spectral band. The angular filtering element (Ei) comprises a first nanostructured, band-pass, spectral filter (11i, 301) and a second nanostructured, band-pass, spectral filter (12i, 302). Each of the first and second spectral filters comprises, respectively, in said spectral band, a first and a second central filtering wavelength that respectively has a first and second angular dispersion curve defined depending on the angle of incidence (θinc) on the optical filtering element (Ei), the curves of angular dispersion being secant about the operating angle of incidence (θi, 1) of the optical filtering element. The invention applies to the production of a selective angular filtering device and to a multidirectional optical detection system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.