SINGLE-MODE OPERATION IN A PULSED TI-SAPPHIRE LASER-OSCILLATOR WITH AGRAZING-INCIDENCE 4-MIRROR CAVITY

We demonstrate stable single mode operation in a pulsed Ti:sapphire la ser oscillator with a novel grazing-incidence four-mirror coupled cavi ty. This cavity consists of a grating, a gain medium, and four mirrors and, therefore, has a four-arm interferometer configuration. Through the interferometric effect, we could suppress the adjacent modes and o btain stable single mode operation with a bandwidth of < 200 MHz. We a lso have developed a general analysis of the laser modes and the thres hold conditions for this configuration and the experimental results ag ree well with the theoretical predictions.