Ring laser gyro and magnetic mirror therefor
US4968136A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1988 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Sep 2, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/0835
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser gyroscope is formed as a sealed, unitary assembly of mirrors optically contacted to a monolithic gyro block without any means, such as Brewster windows, for isolating the laser plasma from any of the mirrors. The mirrors are fabricated with hard multilayer dielectric films which can withstand plasma exposure. A magnetic mirror utilizing the transverse Kerr effect to separate the frequencies of counter-propagating beams, and to avoid lock-in, includes a Ni-Fe alloy layer over which is directly deposited a thin iron or iron alloy layer to form a rotationally switchable Kerr effect combination. The magnetic field for switching is generated by an electric current developed in two pairs of orthogonally disposed wires embedded in the substrate immediately below the iron and Ni-Fe alloy layers. A specially designed multilayer dielectric stack is disposed on one of the mirrors, for example over the iron and Ni-Fe alloy layers on the magnetic mirror, and is configured to suppress S mode oscillation in order to limit the gyro to P mode operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.