Comb optical interference filter
US5170290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1991 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Aug 13, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/007
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
High total transmission, tunable comb filter structures are described which comprise moderately thick layers of optical material having periodic or multiply periodic refractive index modulation features comprising a multiplicity of coherently-coupled, weakly-resonant optical cavities, resulting in and characterized by spectra of high order (5 or higher) relative to a fundamental (lowest order) cavity resonance, consisting of narrow, moderate to high density reflection lines occurring in one or more sets, each set being characterized by lines equally spaced by wave number if optical dispersion is neglected. Filters of the invention can be structured to be tuned, electro-optically or mechanically such that the peaks within a spectral band of interest shift by one harmonic order and/or from one peak position to the next, to reflect or transmit light of any specific wavelength within a band. The individual features defining optical cavities may be thin compared to a wavelength of interest as, for example, when metal films are used as part of a singly periodic comb filter, or may consist of a section whose thickness is equal to several wavelengths, but which is short compared to a cavit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.