Apparatus using induced birefringence to improve laser beam quality
US4935932A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1988 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Aug 15, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/08
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser beam shaper which provides polarized output with a high spatial quality, utilizing induced stress birefringence. The laser beam shaper in which light resonates along a resonant path defined by reflective surfaces includes a solid state medium, such as a Nd:YAG rod which exhibits thermally induced stress birefringence that is of known, azimuthally independent distribution in planes perpendicular to the resonant path. On either side of the medium, quarter-wave retardation plates are provided which create essentially circular polarization of the resonant light within the medium. Sandwiching the quarter-wave plates and the medium are the first and second polarizing elements, both of which are aligned along the same preferred plane. By inducing stress birefringence in the medium, an output beam is produced. A shape defined by the distribution of the birefringence is provided. With media such as YAG, the shape of the beam is round with high quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.