Diameter control of K3Li2-xNb5+xO15+2x single-crystal fibers

Potassium lithium niobate, K3Li2-xNb5+xO15+2x (KLN) single-crystal fibers h ave been grown using the laser-heated pedestal growth (LHPG) technique. Cer amic source rods of K3.00Li1.70Nb5.30O15.6 (KLN53) and K3.00Li1.85Nb5.15O15 .3 (KLN51.5) were adapted to grow the fibers with the: same compositions. T he diameter deviations at various growth rates were estimated. For the (110 ) oriented KLN53 fibers, increase of the growth rate decreased the diameter deviation and the minimum root mean square diameter deviation was 1.8% whe n the growth rate was 66 mm/h. For the (110) oriented KLN51.5 fibers, the m inimum diameter deviation was 1.7% when the growth rate was 40 mm/h. From t he dielectric properties along the grown fiber, the fiber without diameter deviation was determined to have homogeneous composition along the fiber. H owever, the Curie temperature measurements revealed that the composition of the KLN51.5 fiber did not coincide with that of the ceramic source rods.