1. Electro-Optic Property of Mg2+/Er3+-Codoped LiNbO3 Crystal: Mg2+ Concentration Threshold Effect.
- Author
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Du, Wan‐Ying, Zhang, Zi‐Bo, Ren, Shuai, Wong, Wing‐Han, Yu, Dao‐Yin, Pun, Edwin Yue‐Bun, Zhang, De‐Long, and Lupascu, D.
- Subjects
OPTICAL properties of lithium niobate ,ELECTROOPTICS ,METAL ions ,INTERFEROMETRY ,FREE surfaces (Crystallography) ,ALUMINUM films - Abstract
A series of Mg
2+ /Er3+ -codoped congruent LiNbO3 crystals were grown by Czochralski method from the growth melts containing 0.5 mol% Er2 O3 while varied MgO content from 0.0 to 7.0 mol%. The unclamped electro-optic coefficients γ13 and γ33 of these crystals were measured by Mach-Zehnder interferometry. Two different voltage-applying schemes were adopted: one is the DC voltage applied to the crystal via Al films coated onto crystal surfaces and another is via a pair of external Cu slab electrodes. The coefficients measured by the two schemes show similar strong dependence on Mg2+ concentration. The dependence is non-monotonous, dramatic, and unusual, and reveals the features of two Mg2+ concentration thresholds of optical damage: one in the Mg2+ concentration range of 1.2-2.0 mol% (in crystal) and another in 4.5-5.0 mol%. Around the threshold the electro-optic coefficient decreases abruptly at first and then recovers quickly, and the coefficient drops by >20% (12%) at the first (second) threshold, which exceeds the error 3% considerably. The dramatic behavior is qualitatively explained on the basis of the EO coefficient model of LiNbO3 and the defect structure model for Mg2+ -doped LiNbO3 . [ABSTRACT FROM AUTHOR]- Published
- 2017
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