GaSxSe1−x compounds for nonlinear optics

We measure the nonlinearity and transparency of mixed GaS
_x
Se
_1-x
crystals and show that GaS
_0.4
Se
_0.6
is a promising nonlinear material for mid-IR (>5 mum) OPO operation without two-photon absorption for a pump wavelength of 1064 nm.