Design and Optimization of Proton Exchanged Integrated Electro-Optic Modulators in X-Cut Lithium Niobate Thin Film

Huangpu Han,Bingxi Xiang,Guangyue Chai,Shuangchen Ruan,Tao Lin

doi:10.3390/cryst9110549

Huangpu Han, Bingxi Xiang + Show 3 more

Open Access

https://doi.org/10.3390/cryst9110549

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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.

Highlights

Electro-Optic (E-O) modulators have recently attracted growing attention in ultra-compact photonic integrated circuits (PICs) [1]
The Mach-Zehnder interferometer (M-ZI) is one of the most important interference structures in modulators because of its simple design and manufacture, with the existence of a reference arm that compensates for the common-mode effect [3]
High-refractive-index contrast in the form of lithium niobate thin film bonded to a SiO2 layer has emerged as an ideal platform for integrated high-performance modulators [16,17,18,19]

Summary

Introduction

Electro-Optic (E-O) modulators have recently attracted growing attention in ultra-compact photonic integrated circuits (PICs) [1]. They have extensive applications in optical telecommunication networks and microwave-photonic systems [2]. Due to the high E-O coefficient (r33 = 31.2 pm/V) in LN, high-quality E-O modulators of this type are very valuable in optical communication [11,12,13,14,15]. A basic challenge in the production of M–ZI modulators in LNOI is the fabrication of high-quality waveguide structures. To the best of the authors’ knowledge, to date there have been few reports on proton-exchanged electro-optic modulators in LNOI [23]. The optimized half-wave voltage-length product (Vπ·L) was approximately 10.2 V·cm

Device Design and Methods

Discussion

Conclusions