Dynamic multiple wavelength filter using a stratified volume holographic optical element
US5640256A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1996 |
| Grant date | Jun 17, 1997 |
| Priority date | — |
| Expiry date | Jan 25, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/055
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A dynamic multiple-wavelength filter which selects at least one wavelength from a beam of radiation incident on a Stratified volume Holographic Optical Element (SVHOE) in accordance with the Bragg condition. The SVHOE has a number n of grating layers i and a hologram of a grating vector K.sup.i is recorded in each grating layer i. A number n-1 of buffer layers are interposed between grating layers i such that the layers SVHOE presents an alternating structure of grating and buffer layers. The filter has a diffraction efficiency control, preferably based on the ECD effect, for selectively varying the diffraction efficiency .eta. in at least one grating layer i to select from the beam of radiation a narrow bandwidth centered about Bragg wavelength .lambda..sub.B.sup.i of grating layer i.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.