KILOHERTZ FEMTOSECOND UV-PUMPED VISIBLE BETA-BARIUM BORATE AND LITHIUM TRIBORATE OPTICAL PARAMETRIC GENERATOR AND AMPLIFIER

We demonstrate optical parametric generation and amplification of femt osecond pulses in the entire visible range using type-I phase-matched beta-barium borate and lithium triborate crystals pumped by the freque ncy-doubled output of a Ti:sapphire regenerative amplifier at 395 nm. The output is tunable from 470 to 770 nm with a pulse width of similar to 170 fs at a repetition rate of 1 kHz and a a maximum output energy of similar to 1.1 mu J/pulse. The visible optical parametric amplifie r output was then frequency doubled and sum frequency mixed with the f undamental output of Ti:sapphire at 790 nm to produce UV pulses with a conversion efficiency of greater than 25%. The second harmonic genera ted UV pulses are tunable from 240 to 380 nm with a maximum pulse ener gy of similar to 260 nJ/pulse. (C) 1997 Optical Society of America.