Thermal expansion of monoclinic KYbxY1-x(WO4)2 laser crystals

Potassium-yttrium tungstate single crystals KYb x Y 1-x (WO 4 ) 2 of high structural quality are grown by the modified Czochralski method. The crystals were grown using so-called dynamic growth regime, optimal temperature gradients at the crystallisation front were determined. The thermal expansion coefficients of KYb x Y 1-x (WO 4 ) 2 in the directions of the optical indicatrix axes N p , N m and N g are determined using the dilatometric technique. The dependence of thermal expansion coefficients on the temperature in the range of 330–573 K and ytterbium content x from 0 to 1.0 is discussed.