Dependence on excitation polarization and crystal orientation for terahertz radiation generation in a BaGa4Se7 crystal.

Optical rectification is experimentally investigated in a biaxial BaGa4Se7 crystal by considering various combinations of near-infrared excitation polarizations and crystal orientations. The highest terahertz radiation is produced along the Z crystallo-physical direction of the BaGa4Se7 crystal. Despite the optical complexity of the BaGa4Se7 crystal in the terahertz spectral regime, this systematic experimental investigation determines the optimal excitation polarization and crystal orientation for the optical rectification process.