Abstract

The diode laser pumped Nd³⁺ solid-state laser with intracavity frequency doubling in KTiOPO₄ (KTP) is attracted recently much attention. This laser can be used for the realizing of compact and stable green laser source. Unfortunately, the laser has an amplitude instability in the second-harmonic output due to longitudinal mode coupling through sum-frequency generation¹. This problem can be eliminated by allowing only single mode operation. One of the techniques is to use a birefringent filter formed with a polarizer and KTP-crystal as a waveplate. Earlier, a Brewster angle cut Nd:YAG crystal² and an off-axially cut Nd:YVO₄ crystal³ were suggested as a polarizing elements. These ways made the laser geometry more complicated.

© 1996 IEEE