Irradiation effects on the optical properties of a new NLO mixed borate crystal

Single crystals of novel non-linear optical material, barium strontium borate, have been grown in our laboratory by employing a low temperature solution technique for the first time. These crystals are grown up to a size of 20 mm×10 mm×1 mm and they exhibit good non-linear optical properties. As grown faces of these mixed borate crystals are irradiated by 8-MeV electrons as well as silver ions of 120 MeV. The dielectric properties and the refractive indices of these crystals are studied before and after irradiation. It is found that there is an increase in the dielectric constant due to swift heavy ion irradiation as well as due to electron irradiation. A considerable change in the values of refractive indices is observed due to irradiation in both cases. The UV-visible spectra showed no new bands in both cases. The observed results and the possibility of fabricating optical waveguides in these crystals are discussed.