Structure and optical properties of as-grown potassium lithium niobate crystals

Potassium lithium niobate (KLN) is an attractive material because of the se nsitive interaction between the optical properties and the structure which depend on the chemical composition. Crack-free and homogeneous KLN crystals have been grown using the micro-pulling-down (mu-PD) method, and the corre lations between the composition and the optical properties were considered. The second harmonic generation (SHG) property, which is converted to blue laser light with half wavelength by the red irradiation of the laser, was f ound in the mu-PD KLN crystals, and the effect of compositional change on t he structure depended on the polar atomic displacements which increased wit h decreasing Nb content.