Modeling and Analysis of Zinc Diffusion Effect within InP-Based Mach-Zehnder Modulators

We investigate the influence of Zinc diffusion on the modulation efficiency and optical insertion loss of InP-based MZI modulators. By analyzing the electric-optical field distribution and free-carrier absorption loss of three types of Zinc diffusion profiles, the mechanisms between Zn diffusion and modulation efficiency and optical insertion loss inside MZI modulators are systematically studied. We show that InP-based MZI modulator modulation efficiency is limited by electro-optic field distribution overlap and optical mode interacts with p-type dopant increases device insertion loss when Zn diffuses during MOCVD epitaxial process.