Growth and optical properties of (K0.62Na0.38)2Al2B2O7 crystal

► (K0.62Na0.38)2Al2B2O7 crystal with reactants of K2CO3: Na2CO3 = 1:1 was obtained. ► The transmittance of (K0.62Na0.38)2Al2B2O7 crystal increased below 300 nm. ► The conversion efficiency of FOHG reached 20.1% for Nd:YAG lasers. ► A 350 mW average output power was obtained through FOHG of Nd:YAG laser.