HIGH-EFFICIENCY INTRACAVITY FREQUENCY-DOUBLED CW AND TUNABLE TI-SAPPHIRE LASER

An efficient and stable intracavity frequency-doubled cw and tunable T i:sapphire laser has been developed using a critically phase-matched, temperature-tuned lithium triborate crystal. Ultraviolet coherent radi ation tunable from 400 nm to 395 nm has been obtained with maximum out put power of 460 mW. The frequency-doubling efficiency, the ratio of t he converted second-harmonic power to the fundamental output capabilit y, is over 70%. The effects on the conversion efficiency of the fundam ental oval-shaped beam, multimode structure and harmonic-reflection-mi rror enhancement are analyzed. The temporal stability of the harmonic output power and the crystal coating damage are examined and discussed .