MORPHOLOGICAL ASPECTS OF POTASSIUM LITHIUM-NIOBATE CRYSTALS WITH ACICULAR HABIT GROWN BY THE MICRO-PULLING-DOWN METHOD

Crack free a- and c-oriented potassium lithium niobate (K3Li2-xNb5+xO1 5+2x, KLN) micro single crystals, with diameter up to 500 mu m and len gth up to 10 cm, were grown by the micro-pulling-down (mu-PD) method i n the melt composition range of -0.6 less than or equal to x less than or equal to 0.5. Whereas a-oriented crystals show mostly rectangular cross-sections with somewhat elongated dimension parallel to the c-axi s, c-oriented crystals possess polygonal cross-areas, the symmetry of which is affected by the symmetry of the heat field very sensitively. It has been shown that the Nb:Li relation in the starting melt is of c onsiderable influence on the mode of growth kinetics. The second harmo nic generation of Ti:sapphire and (Ga,Al)As lasers was provided succes sfully.