OPTIMIZED KERR LENS MODE-LOCKING OF A PULSED ND-KGW LASER

We report on the generation of ultrashort laser pulses using Kerr lens mode-locking (KLM) of a flashlamp pumped Nd:KGW laser, Acousto-optic mode-locking and a fast electro-optic feedback loop is used to maintai n high stability of the pulse parameters. The nonlinear index of refra ction of the Kerr medium can be varied by a factor of two without affe cting the pulse duration of 1.7 ps (FNHM). This is, to the best of our knowledge, the shortest pulse duration obtained with a Nd:KGW laser. A detailed ABCD-analysis of the resonator design relevant for KLM is g iven and compared with experimental results. Efficient amplification o f the ultrashort pulses is obtained in a double pass amplifier with a moderate increase of pulse duration to 2.3 ps. The long pulse trains o f approximately 1000 pulses at a single pulse energy of 10 mu J and a repetition rate of 40 Hz are very well suited for synchronously pumpin g a dye laser or an optical parametric oscillator.