A Raman-scattering study of the vibrational modes in a BiB3O6 crystal was conducted at room temperature. The numbers of external and internal modes obtained in experiment are consistent with the results of a group theoretical analysis. The Raman lines below, 300cm-1 and from, 300 to 1600cm-1 are assigned to the external modes of the lattice and internal vibrations of the BO3 and BO4 subunits of the BiB3O6 structure, respectively.

High purity KTiOPO4 (KTP) crystals have been grown using a flux method. The quality, SHG e ciency and damage threshold of KTP crystals grown from high purity reagents were compared with those grown from commercial reagents. Experimental results indicate that KTP crystals using a high purity charge contain less impurities and possess higher SHG efficiency and damage threshold than do crystals grown from commercial reagents. It is proposed that decreasing the concentrations of impurities is an effective way of raising the damage threshold for KTP crystals.