Mercury thiogallate mid-infrared femtosecond optical parametric generator pumped at 1.25 mu m by a Cr : forsterite regenerative amplifier

We demonstrate a novel traveling-wave-type optical parametric generator bas ed on 1.25-mu m pumping of HgGa2S4 that produces tunable, high-power, trans form-limited proportional to 200-fs pulses in the mid-IR from 5 to 9 mu m. Output idler energies on the microjoule level are obtained with maximum con version efficiency of 11% for the amplifier stage, which is more than two t imes better than the results obtained with an analogous sample of the widel y spread material AgGaS2. (C) 2000 Optical Society of America.