Second-harmonic generation from a KBe2BO3F2 crystal in the deep ultraviolet

By use of KBe2BO3F2 (KBBF) crystal with a size of 10 mm x 10 mm x 1.2 mm and a special prism-coupling technique (PCT), fourth-harmonic generation of Ti:sapphire laser systems from 200 to 179.4 run 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. (C) 2002 Optical Society of America.