Interferometer gyro using heterodyne phase detection without severe light source coherence requirements
US4208128A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1978 |
| Grant date | Jun 17, 1980 |
| Priority date | — |
| Expiry date | Aug 23, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C19/72
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometer gyro employing a coiled optical fiber includes a pair of acousto-optic modulators to modulate first and second frequencies onto two components divided from the light of a light source. The light source need not exhibit the high degree of source coherence heretofore required, and can be an incandescent bulb in many applications. The first and second modulated light components are injected in opposite or counter-rotating directions into the optical fiber wherein they experience phase changes due to the apparent change in optical length of the optical fiber upon rotation of the fiber about an axis of sensitivity. The light components are then, after being removed from the fiber, combined and compared with the signals applied at the input. The phase difference therebetween is then established to measure the rate of rotation of the optical fiber about the axis of sensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.