Narrow bandwidth, picosecond, 1064  nm pumped optical parametric generator for the mid-IR based on HgGa₂S₄

We report on optical parametric generation in a mercury thiogallate (HgGa2S4) crystal pumped by 16 ps, 1064 nm pulses at 250 kHz. A broad tuning range extending from 1.19 to 1.47 μm (signal) and from 3.85 to 10 μm (idler) is achieved. Narrow bandwidth, quasi-Fourier limited operation with high beam quality for the signal/idler pulses and >14% pump depletion is obtained by continuous wave seed injection at 1.29 μm.