Non-critical OPO based on periodically-poled KTP crystal generating ∼ 250 ps idler pulses at 1–10 kHz

Idler pulses at 2.8 μm with energy of ∼ 50 μJ and ∼ 250 ps pulse duration are obtained from a short-cavity, singly-resonant OPO based on PPKTP, pumped by a 1–10 kHz, 500 ps, 1064 nm laser source.