Compensated dual cavity laser gyro
US4647204A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1985 |
| Grant date | Mar 3, 1987 |
| Priority date | — |
| Expiry date | Aug 16, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C19/66
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser gyro has two adjacent laser cavities which are parallel and separated so that there are no common parts between the respective mode volumes. Each cavity supports a wave traveling in only one direction. Passive optical means external to the cavities are provided for establishing these directions of travel. Additionally, the passive means allows quick reversal of these directions of travel, which allows for the compensation of all frequency shifts which are not proportional to rotations. The passive reversal is accomplished with an optical element that is controlled to act alternately as a window and then as a mirror for light of only one wavelength. The gyro produces two output waves whose frequencies are shifted in opposite directions by rotation. The two frequencies are mixed and the resultant beat frequency is detected by optical heterodyning. The response is a linear output signal. Very low rotation rates may be sensed down to zero rotation and its accuracy is limited by quantum effects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.