Nonstoichiometric dependences and the influence of ion-doping on the electrooptic effect in lithium niobate crystals: application to optical devices for optical communication systems in the coming generation

摘要

The nonstoichiometric dependences of the electrooptic coefficients in lithium niobate (LN) crystals and the influence of doping with Fe-ions, Er-ions and Er-ions are measured (at 633nm) precisely and investigated in detail. The electorooptic coefficient r{sub}33 increases with an in Li/Nb ratio. The r{sub}33 in the stoichiometric LN is 1.14 times as 1arge as that in the congruent LN crystal. An increase of more than 30% in electorooptic coefficients can be obtained by doping with Ce- or Fe-ions. Some of the samples are measured at the longer wavelength for applications to optical fiber communication wavelength region