High power laser with focusing mirror sets
US5052017A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1990 |
| Grant date | Sep 24, 1991 |
| Priority date | — |
| Expiry date | Jun 8, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/08072
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A laser system employing one or more mirror sets having substantially astigmatism-free focusing power sufficient to maintain a desired laser beam diameter, for example, to compensate for thermally-induced distributed lensing. In one class of preferred embodiments, the invention is a high power gas laser system having a folded optical cavity with a periodic intracavity refocusing means to compensate for distributed negative thermal lensing in the hot plasma that comprises the active medium, and thus maintain a substantially constant beam diameter throughout the optical cavity. The periodic intracavity refocusing means preferably includes a corner mirror set (including at least one curved mirror and at least one other mirror) at each corner of the folded optical cavity. In one preferred embodiment, each corner mirror set is a mirror pair including a spherical mirror and cylindrical mirror. In another preferred embodiment, each corner mirror set comprises three mirrors (including three spherical mirrors, or two spherical mirrors and a planar mirror). In another class of preferred embodiments, the inventive focusing mirror sets are not included within the optical cavity of a high power…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.