Induced Li-site vacancies and non-linear optical behavior of doped lithiumniobate crystals

Second-order non-linear optical (NLO) properties of doped lithium niobate ( LN) crystals (abbreviated as M:LN, where M = Mg2+, Zn2+, and In3+, respecti vely) have been quantitatively studied from the chemical bond viewpoint. Ou r results show that the second-order NLO response of doped LN crystals decr eases remarkably with increasing dopant concentration in the crystal. The a pproximately linear composition-property correlation in these doped LN crys tals is quantitatively expressed in the current work. A comparison of the d ifferent influences of Mg, Zn and In dopants. respectively, shows that thes e dopants affect the NLO properties of LN crystals mainly via the number of Li-site vacancies induced. (C) 2001 Elsevier Science B.V. All rights reser ved.