Tunable UV radiation near 215 nm was produced by frequency quadrupling the 860-nm emission of a mode-locked external-cavity compound semiconductor laser containing a tapered GaAlAs amplifier. A KNbO3 crystal generated the 430-nm second harmonic, which was doubled by a β-BaB2O4 crystal, producing tunable UV radiation with as much as 15 µW of average power.
© 1995 Optical Society of America
Lew Goldberg and Dahv A. V. Kliner, "Deep-UV generation by frequency quadrupling of a high-power GaAlAs semiconductor laser," Opt. Lett. 20, 1145-1147 (1995)