**Huangpu Han 1,2, Bingxi Xiang 3,\*, Tao Lin 3, Guangyue Chai <sup>3</sup> and Shuangchen Ruan <sup>3</sup>**


Received: 29 September 2019; Accepted: 22 October 2019; Published: 24 October 2019

**Abstract:** In this study, we designed, simulated, and optimized proton exchanged integrated Mach-Zehnder modulators in a 0.5-μm-thick x-cut lithium niobate thin film. The single-mode conditions, the mode distributions, and the optical power distribution of the lithium niobate channel waveguides are discussed and compared in this study. The design parameters of the Y-branch and the separation distances between the electrodes were optimized. The relationship between the half-wave voltage length production of the electro-optic modulators and the thickness of the proton exchanged region was studied.

**Keywords:** electro-optic modulator; lithium niobate thin film; proton exchange; Mach-Zehnder; integrated optics devices
