Sensor with an optical interferometric pick-off
US6064630A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Jul 13, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0077
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for measuring changes in an environmental parameter such as displacement, velocity, acceleration, or pressure, includes a laser for providing a pulsed, coherent light signal, and an interferometer having a first and second optical legs of unequal optical path lengths. The signal is split into first and second beams that are directed into the first and second optical legs. Either a fixed mirror disposed on a frame or a moving mirror on one side of the proof mass reflects the first beam received at the end of the first optical leg. The frame also suspends a proof mass at opposite ends. An optical pick-off embodied in a movable mirror formed on the proof mass reflects the second beam received from the end of the second optical leg. The proof mass with mirror moves in response to changes in the value of the parameter to be measured. An optical coupler combines the first and second beams after they have been reflected back into their respective optical legs, producing an interference signal, which is detected by an optical detector. The detector generates an electronic signal, which is analyzed in a microcomputer. To compensate for gravity, the proof mass has an asymmetrical pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.