Study on photodamage of Mg:Er:LiNbO_3 waveguide substrate

摘要

Doped 0.5mol% Er_2O_3 and (2,4,5,6)mol% MgO in LiNbO_3 crystal, Mg:Er:LiNbO_3 crystals were grown by Czochralski technique.The IR transmission spectra of those crystals were measured. The OH~- absorption peak of Mg(2mol%):Er:LiNbO_3 and Mg(4mol%):Er:LiNbO_3 at about 3486 cm~(-1),while that of Mg(5mol%):Er:LiNbO_3 and Mg(6mol%):Er:LiNbO_3 at about 3535 cm~(-1) The shifting mechanism of OH~- absorption peak was discussed based on the Li-site vacancy model. Using m-line method tested the photodamage of Mg:Er:LiNbO_3 waveguide substrate. The photodamage resistant ability of Mg:Er:LiNbO_3 is higher than that of Er:LiNbO_3. The photodamage resistant ability of Mg(5mol%):Er:LiNbO_3 waveguide substrate improves two orders than that of Er:LiNbO_3.