The sphere method: A new technique in linear and non-linear crystalline optical studies

Abstract

We suggest a new method of optical characterization of non-linear materials which only requires knowledge of the orientation symmetry of the crystals studied. This method necessitates cutting only one crystal in this case KTiOPO 4(KTP), in sphere with a diameter of about 5 mm. The sphere is placed at the center of an Euler circle and illuminated with laser beams. Walk off angles are measured at 0.6328 μm. The directions of optical axes are determined at λ=0.6328 μm and λ=1.064 μm. We also establish the phase matching directions of KTP for the SHG of type II (1.064 μm/0.532 μm) directly.