Pulse broadening and shaping by parametric amplification of short laser pulses in transverse-pumping geometry

We have made a feasibility study on how to use transversely pumped counterpropagating optical parametric amplification to amplify short laser pulses. To achieve a large amplification factor, one should use long laser pulses for pumping. Because of its counterpropagating nature, our geometry can lead to much larger broadening for the parametric pulses. We have studied the temporal behaviors of amplified pulses and output pulses at difference frequency as a function of the pump power and the pulse width of the input beam. One can see that the temporal behaviors are quite sensitive to the pump power close to the threshold for cw parametric oscillation. (C) 2000 Optical Society of America [S0740-3224(00)00804-3] OCIS codes: 190.2620, 190.2640, 190.4970, 230.4170, 320.2250, 320.7130.