Design Optimization of Silicon and Lithium Niobate Hybrid Integrated Traveling-Wave Mach-Zehnder Modulator

Junming Cai, Changjian Guo, Chao Lu, Alan Pak Tao Lau, Pengxin Chen, Liu Liu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Lithium niobate, dueto its strong electro-optic effect, is an excellent material for high-performance optical modulators. Hybrid integration of thin film lithium niobate and silicon photonic circuits makes it possible to fully exploit potentials of the two material systems. In this paper, we introduce a detailed design procedure for silicon and lithium niobate hybrid integrated modulator using coplanar line electrodes based on Mach-Zehnder interferometer push-pull configuration. A multiphysics model for the crossing section of the modulation section is proposed and analyzed. The results show that optimizing solely the V_{\pi } L product would not lead to the best 3-dB bandwidth for a certain half-wave voltage due to the increased microwave losses. There exists an optimal ground-signal electrode gap value, which is about 8-9{\,\mu m} for the present modulator structure. For these optimized structures, 3-dB bandwidths can reach 45 GHz and 137 GHz with half-wave voltages of 2 V and 4 V, respectively, for a lithium niobate waveguide total thickness of 600 nm and a ridge height of 200 nm.

Original languageEnglish
Article number9461596
JournalIEEE Photonics Journal
Volume13
Issue number4
DOIs
Publication statusPublished - Aug 2021

Keywords

  • hybride Mach-Zehnder modulator
  • Lithium niobate

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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