The effect of NaCl melt-additive on the growth and morphology of LiB3O5 (LBO) crystals

The growth of nonlinear optical crystals of large size and excellent qualit y is of prime importance for frequency conversion applications. In the flux growth of LiB3O5 (LBO), the presence of extended BO3 and BO4 chain-like st ructures gives rise to highly viscous melts. As a consequence, mass transpo rt is restricted and the depletion of material at the melt-crystal interfac e results in unstable hopper growth. The addition of small amounts of NaCl to the melt is effective in breaking BO4 bond chains, The resulting reducti on in viscosity facilitates an increase in growth rate by up to a factor of 3. However, the incorporation of NaCl into the lattice may have an adverse effect on crystal quality, In the present study. LBO crystals of typical d imension 30 x 30 x 26mm(3) were grown by top-seeded solution from berate fl uxes doped with Z and 4 mol% NaCl, and without NaCl, Changes in growth and morphology are described as a function of melt dopant concentration. Laser damage threshold will be discussed in relation to the concentration of NaCl in the crystal. (C) 2001 Published by Elsevier Science B.V.