High-extraction efficiency annular resonator
US4744090A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1985 |
| Grant date | May 10, 1988 |
| Priority date | — |
| Expiry date | Jul 8, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/081
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A standing-wave annular laser resonator providing high energy extraction efficiency and good beam quality without the need for polarization coatings. The resonator includes an axicon, a scraper mirror, and a rear mirror system. A critical feature of the configuration is that the axicon has an inner conical mirror of which the apex is offset from the usual position, such that a radial beam reflected from an outer conical mirror has one portion that bypasses the inner mirror without impinging on it. This portion of the radial beam is reflected back along an annular path and makes two more passes through an annular gain region before becoming available for outcoupling around the scraper mirror. The rear mirror system retroreflects and annular beam back on itself in inverted form, without introducing any polarization mixing. The rear mirror system may take the form of a conical mirror and a plane back mirror, or a concave retroreflecting cone, or a convexly curved conical mirror and a concavely curved back mirror.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.