By use of KBe<sub>2</sub>BO<sub>3</sub>F<sub>2</sub> (KBBF) crystal with a size of 10 mm×10 mm ×1.2 mm and a special prism-coupling technique (PCT), fourth-harmonic generation of Ti:sapphire laser systems from 200 to 179.4 nm has been achieved. Moreover, with a Ti:sapphire laser with a 50-fs pulse duration and a 1-kHz repetition rate, conversion efficiency as high as 13% from 400 to 200 nm without any surface-loss correction has also been obtained. The data show that with the PCT a KBBF crystal can produce deep-UV coherent light with measurable power output.
© 2002 Optical Society of America
Chuangtian Chen, Junhua Lu, T. Togashi, T. Suganuma, T. Sekikawa, S. Watanabe, Zuyan Xu, and Jiyang Wang, "Second-harmonic generation from a KBe2 BO3F2 crystal in the deep ultraviolet," Opt. Lett. 27, 637-639 (2002)