Studies on the Crystal Growth and Characterization of Large Size Sr:LCB Single Crystals

Extending the shortest second harmonic generation output wavelength of nonlinear optical crystals into the deep ultraviolet (UV) range is important for their application as frequency conversion devices for an advanced laser. The doping of ions with a large atomic number is believed to be an effective way to realize a shorter SHG output wavelength. In this work, large-sized Sr2+-doped La2CaB10O19 (Sr:LCB) crystals with nominal ratios of 10%, 15% and 30% were grown by the top-seeded solution growth method. The measured lattice parameters of the grown Sr:LCB are nearly the same as that of the LCB crystal, and the rocking curves reveal that the grown Sr:LCB crystals are of high quality. Sr: LCB crystals have a UV cut-off edge of 168 nm. The refractive index of the Sr:LCB crystals was measured, based on which the Sellmeier equations of the Sr:LCB crystals were fitted. The calculated shortest SHG output wavelength for Type I phase matching is 270.5 nm, which is 17.5 nm shorter than that of LCB crystals (288 nm). The characterization results demonstrate that Sr:LCB is a potential nonlinear optical crystal for the deep UV range.