Tunable visible high-repetition-rate solid-state lasers

Summary form only given. Second-harmonic generation (SHG) of infrared vibronic lasers is emerging as an attractive alternative approach for the development of broadly tunable visible solid-state lasers. SHG of Ti:sapphire has been widely used for tunable blue and ultraviolet lasers, and recently operation at longer visible wavelengths has been achieved by SHG of gain-switched Cr/sup 4+/ doped forsterite and YAG lasers. Most reported gain-switched Cr/sup 4+/ lasers have been pumped at around 10 Hz. However, higher operating repetition rates in excess of 1 kHz are often preferable for applications in areas such as LIDAR and biomedicine. A number of researchers, including ourselves, have recently demonstrated kHz repetition rate Cr/sup 4+/ lasers and regenerative amplification of ultrashort pulses. We report for the first time, to our knowledge, intracavity SHG of forsterite for high-repetition-rate visible wavelength operation. Conversion efficiencies are more than four times those reported recently for extra-cavity doubling.