LiGaTe/sub 2/ a new highly nonlinear chalcopyrite optical crystal for the mid-IR

The growth of single crystals of LiGaTe/sub 2/ (LOT), a new noncentrosymmetric mid-IR crystal with chalcopyrite structure. For broadband frequency conversion applications it is very interesting that the band gap of LOT (2.3 eV) is much larger than the bandgap of the isostructural AgGaTe/sub 2/ (1.316 eV). Here we report on the linear (birefringence) and nonlinear optical properties of LGT and demonstrate phase- matched second harmonic generation (SHG).