High-powder sum frequency generation of 230.8-223.2 nm radiation in BBO crystals

Continuously tunable second-harmonic generation (SHG) of 294.9-280.5 nmradiation was obtained by a Q-switched Nd:YAG laser-pumped Rh.-G dye laser in a 45 o -cut βBaB 2 O 4 b(BBO) crystal. The output energy of SHG is about 8 mJ arouns 285 nm. Continuously tunable output over the range of 230.8-223.2 nm was also obtained by sum-frequency mixing between the residual pump fundamental wave (1064 nm) and the second-harmonic wave of the Rh.6G dye laser in another 45 o -cut BBo crystal. The sum-frequency output energy is about 120μJ around 227 nm, and the corresponding peak power is about 12 kW. The key techniquesfor sum frequency generation (SFG) are indicated