Determination of the center composition of gradient-activated lithium niobate crystals doped with magnesium and chromium

Abstract

Investigations of the defect structure of a gradient-activated stoichiometric LiNbO₃:Mg²⁺, Cr³⁺ crystal, in which the chromium concentration has a constant value of 0.1 at. % along the crystal growth axis, and the magnesium concentration changes smoothly from 5.5 to 2.0 al. %. The threshold concentration of Mg²⁺ ions (2.35 at. %) in these crystals with a concentration width of change in the center composition (Cr optical center and its nearest neighbors) of 0.09 at. % Mg²⁺ ions is established..