US005835513A [ii] Patent Number: 5,835,513  Date of Patent: Nov. 10, 1998
 Q-SWITCHED LASER SYSTEM PROVIDING UV LIGHT
 Inventors: Jan-Willem Pieterse, San Jose; Alan
B. Petersen, Palo Alto; Chris Pohalski,
Mountain View; Emily Cheng,
Sunnyvale; Randall Lane; William L.
Nighan, Jr., both ol Menlo Park, all of
 Assignee: Spectra Physics, Inc., Mt. View, Calif.
 Appl. No.: 780,495
 Filed: Jan. 8, 1997
 Int. CI. HOIS 3/10
 U.S. CI 372/22; 359/328
 Field of Search 372/22, 5, 10;
 References Cited
U.S. PATENT DOCUMENTS
5,274,650 12/1993 Amano 372/22
A diode pumped laser includes a high reflector and an output coupler defining a resonator. The resonator includes a gain medium and a Q-switch and produces a fundamental beam. A first non-linear crystal is positioned extra-cavity of the resonator along a path of the fundamental beam. The first non-linear crystal generates a second harmonic beam from the fundamental beam. The first non-linear crystal is critically phased matched. A second non-linear crystal is portioned extra-cavity of the resonator along a path of the fundamental beam and the path of the second harmonic beam. The second non-linear crystal produces a third harmonic beam. The second non-linear crystal is critically phased matched.
15 Claims, 3 Drawing Sheets