Spectral band-pass filter having high selectivity and controlled polarization
US9052454B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 15, 2011 |
| Grant date | Jun 9, 2015 |
| Priority date | — |
| Expiry date | Feb 28, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2207/101
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
According to one aspect, the invention relates a spectral band-pass filter, which is optimized for the transmission of an incident wave at at least a first given central wavelength λ0, and which includes: a metal grating having a thickness (t) greater than approximately λ0/50 and including at least a first set of substantially identical, parallel slots having a width (W) less than around λ0/10, and being spaced apart periodically or quasi-periodically according to a first period that is less than said first central wavelength, a layer of dielectric material having a thickness (h) and a given refractive index (ng), which is coupled to the metal grating to form a waveguide for the waves diffracted by the grating, said first period of the grating being designed such that only orders 0 and ±1 of a wave having normal incidence and a wavelength λ0 are diffracted in the layer of dielectric material, the assembly of the dielectric layer and grating being suspended, during use, in a fluid having a refractive index of close to 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.