Optical filters derived from spherical lenses and method of fabrication thereof
US6525881B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 5, 2001 |
| Grant date | Feb 25, 2003 |
| Priority date | — |
| Expiry date | Jul 25, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical filtering element with minimized edge effects, larger clear center aperture, and thermally stable bonding area. The element consists of a modified ball lens. The glass material that comprises the ball lens can be selected from a variety of thermally matched glass specific to the intended application such as BK7, SiO2, et cetera. The lens is polished on two sides so that the polished surfaces are nearly parallel. The polished ball lens(es) are then loaded into a coating fixture and then into a coating chamber. Multiple dielectric layers are applied to one of the polished surfaces, creating a spectral modifying filter. The other side is coated with an anti-reflection coating (some applications do not require the anti-reflection coating). At the completion of the coating run, the now polished and coated ball lenses can be spectrally measured and binned for use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.