Second Order Susceptibilities and Electro-Optic Coefficients of ZN-Indiffused LiNbO₃ Waveguides

Abstract

The electro-optic coefficients r ₃₃ and r ₁₃ and the second order susceptibility χ ⁽²⁾ ₃₃ have been measured in Zn-in-diffused waveguides on congruent LiNbO ₃ . Absolute measurements of r ₃₃ and r ₁₃ have been carried out with a Mach-Zehnder modulating technique and the obtained values, r ₃₃ = 14.6 ± 0.9 pm/V and r ₁₃ = 3.3 ± 0.2 pm/V, show an appreciable decrease with regard to that of congruent LiNbO ₃ . Measurements of χ ⁽²⁾ ₃₃ relative to the substrate have been performed in the strong absorption regime and the obtained value equals that of bulk LiNbO ₃ .

Keywords:

• Waveguide
• Zinc in-diffusion
• LiNbO₃
• electro-optic coefficients
• nonlinear coefficients

Acknowledgments

This work was supported by the Spanish Ministerio de Educación y Ciencia under grant MAT2005-06359-C03-01. Olga Caballero is supported by a fellowship of the Comunidad Autónoma de Madrid. We would also like to thank Professor J. M. Cabrera for many fruitful discussions and comments.