Narrow-bandwidth, ~100 ps, seeded optical parametric generation in CdSiP2 pumped by Raman shifted pulses at 1198 nm

Low-threshold, efficient optical parametric generation at !4.64 μm is demonstrated using CdSiP2 nonlinear crystal pumped by 150 ps Raman shifted pump pulses at 1198 nm in noncritical configuration at 1 kHz repetition rate. Maximum single pulse idler energy of 6 μJ and total conversion efficiency of 30% are achieved. Seeding at the signal wavelength with a distributed feedback laser diode enables !25 fold narrowing of the bandwidths down to !10 GHz, resulting in a Fourier product of !1 for the !100 ps long signal (1615 nm) and idler (4.64 μm) pulses.