Frequency doubling a Q-switched laser beam by using intracavity Type II phase matching

摘要

A frequency doubler for a Q-switched laser is disclosed in which a Type II SHG crystal is oriented to generate a second harmonic frequency beam in response to the orthogonal components of a fundamental beam. After the fundamental beam makes a round trip through the SHG crystal, any differential phase delays between the orthogonal components due to birefringence are eliminated to improve the efficiency of the cavity.