Fabry-Perot micro filter-detector
US5550373A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1994 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | Dec 30, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/001
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A monolithically constructed infrared, tunable Fabry-Perot cavity filter-detector for spectroscopic detection of particular substances having an absorption line in the wavelength range from 2 to 12 microns. The filter-detector has a hermetically sealed Fabry-Perot cavity that has a mirror which has an adjustable distance relative to another mirror of the cavity. The former mirror is adjusted by piezoelectric film on the mirror support or with piezoelectric stacks or wall supporting the mirror. There may be electrodes situated near the mirrors for capacitive sensing of the distance between the mirrors. Light to be filtered and detected comes in through a window wafer which may have diffractive or refractive microlenses, plus an optional spatial filter. After passing through the window wafer, the light is filtered by the tunable mirrors of the Fabry-Perot cavity. The portion of the light that is passed by the cavity is detected by an infrared microbolometer or a CCD array. The cavity and detector are hermetically sealed in a vacuum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.