Method and apparatus for suppressing off-axis modes in laser and ring laser gyroscopes
US5166949A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1990 |
| Grant date | Nov 24, 1992 |
| Priority date | — |
| Expiry date | Dec 20, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/034
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A dielectric interference film having a central region of one thickness and a peripheral region of a different thickness is superimposed on one of the mirrors of a ring laser gyroscope for the purpose of suppressing off-axis resonant modes that are characteristic of a resonant cavity. The central region is designed to intercept a large portion of the fundamental mode power and a lesser portion of the off-axis mode power. The difference in thickness between the central and peripheral regions causes the reflected light from the two regions to differ in phase by approximately one-half wavelength and destructively interfere. As a result of the imbalance of the fundamental and off-axis mode powers incident on the central region, the reflectivity losses of the off-axis modes are more pronounced than those of the fundamental mode with the result that the off-axis modes are completely suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.