80-MHz difference-frequency generation of femtosecond pulses in the mid-IR using GaS0.4Se0.6

We employ GaS
0.4
Se
0.6
nonlinear crystal for difference-frequency generation between signal and idler of a synchronously pumped femtosecond OPO at 80 MHz achieving continuous tuning from 4 μm (>12 mW) to 12 μm (>0.5 mW).