Growth of high-quality transparent SrB4O7 single crystals with high degradation resistance for DUV laser application

We grew borate crystals, SrB4O7 (SBO), by the top-seeded solution growth (TSSG) method. High-quality transparent SBO single crystals were successfully obtained from the stoichiometric melt by a seed cooling technique. The optical properties of the SBO crystals, which showed wide transparency, high transmittance, and high resistance to optical damage compared with synthetic silica glass and CsLiB6O10 (CLBO) crystals, were evaluated. Our results reveal for the first time that the SBO crystals exhibit outstanding degradation resistance at a DUV wavelength of 266 nm.