Pumping picosecond optical parametric oscillators by a pulsed Nd : YAG laser mode locked using a nonlinear mirror

We report on the performances of the mode locking of a flash-lamp-pumped Nd :YAG laser using a frequency-doubling nonlinear mirror combined with a two- photon absorber. Pulse lengths from 12 to 8 ps are generated. We show that the flat shape of the pulse-train envelope generated by the oscillator is a dapted for the synchronous pumping of optical parametric oscillators and we demonstrate the efficient generation of an infrared beam tunable from 3800 to 1100 cm(-1) with bandwidth of 2 cm(-1) in one single conversion stage i n LiNbO3 or AgGaS2. The "all-solid-state" laser system enables surface sum- frequency generation spectroscopy to be performed with high sensitivity and high resolution. (C) 2001 American Institute of Physics.