Medical laser apparatus, high powered red laser used in same, and laser resonator with non-linear output
US5130997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1990 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Dec 18, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/115
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser system generates suitable laser power for use in photodynamic therapy, and particularly photodynamic therapy using dyes which undergo desired photodynamic reactions at 659 mm, i.e., Purpurin. The laser system generates a red output power of greater than 4 watts. For the therapeutic applications, a means for delivering the red beam to therapeutic sites is provided. The laser system provides for a frequency doubled solid-state laser system in which the non-linear birefringent crystal used to provide frequency doubling is mounted adjacent a flat mirror whereby losses due to walkoff of the beam caused by the crystal are minimized. The laser resonant cavity defined by one flat and one other mirror, which may be stabilized by means, such as thermal lensing in the solid-state gain medium, inside the cavity. A frequency doubled Nd:YAG rod in such cavity tuned to 1.319 microns with a KTP frequency doubling crystal for generates an output beam at 0.659 microns via type II phase matching required for photodynamic therapy in conjunction with a suitable PDT compound or dye.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.