Abstract
KLN crystals were grown along the 〈110〉 axis by the TSSG method from different melts with 30–32mol% K2O, 23–27mol% Li2O and 43–46mol% Nb2O5. Lattice constants were measured by the single crystal XRD analysis. Curie temperatures were determined with an LCR meter HP 4284A at 1kHz. The blue SHG characteristics of the KLN crystals were investigated by using a 3900S Ti: sapphire CW tunable laser with the wavelength range of 675–1100nm. It is found that the non-critical phase matching (NCPM) wavelength at room temperature decreases significantly from 974 to 827.4nm with the increase of [K]/[Li] and [Li]/[Nb] ratios in the melts. On the basis of this survey, the melt compositions suitable for the TSSG growth of high quality KLN crystals with high lithium content are outlined, as indicated by the large c-axis lattice constant, high Curie temperature and short NCPM wavelength.