The recently developed chalcopyrite CdSiP2 is employed in a picosecond, 90°-phase-matched synchronously pumped
optical parametric oscillator pumped at 1064 nm, to produce quasi-steady-state idler pulses near 6.4 μm with an energy
as high as 2.8 μJ at 100 MHz. The train of 2 μs long macropulses, each consisting of 200 (picosecond) pulses, follows at
a repetition rate of 25 Hz. This corresponds to an average power of 14 mW. The pump depletion (conversion efficiency)
exceeds 40%. Without intracavity etalon, the 12.6 ps long mid-IR micropulses have a spectral width of 240 GHz.