High-Efficiency Intracavity Frequency-Doubled CW and Tunable Ti:Sapphire Laser

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