Tunable continuous-wave midwave infrared generation using an orientation patterned GaAs crystal with a fan-out grating design

We report the first demonstration of frequency conversion in an orientation patterned GaAs (OPGaAs) crystal with a fan-out grating configuration. Room temperature frequency doubling of a continuous-wave carbon dioxide laser tuned from 9.26 to 10.65 micrometers was obtained using the large-aperture OPGaAs crystal (>3 mm thick, >7.5 mm wide and 40 mm long) with fan-out grating periods ranging between 212.5 μm and 220 μm.