Flux growth and optical properties of Na3La9O3(BO3)8 crystals

Na3La9O3(BO3)8 (NLBO) crystals were grown by the top-seeded solution growth (TSSG) method from three new fluxes: Na2O–B2O3–Li2O, Na2O–B2O3–NaF–LiF and Na2O–B2O3–NaF, respectively. The volatility was investigated. The results showed that the Na2O–B2O3–NaF flux is more suitable than others for growing NLBO crystals. The suitable molar ratio for Na3La9O3(BO3)8, Na2CO3, H3BO3 and NaF is 1.0:(7.5∼5.0):(6.5∼5.0):(8.8∼35.0) with the growth temperature at 920∼980 °C. NLBO crystal size was up to 35×22×10 mm3. The shortest SHG wavelengths for type-I and type-II phase-matching (PM) are 288 nm and 395 nm, respectively.