Low-power electro-optic phase modulator based on multilayer cgraphene/silicon nitride waveguideProject supported by the National Key Research and Development Program of China (Grant No. 2019YFB2203001), the National Natural Science Foundation of China (Grant Nos. 61675087, 61875069, and 61605057), and the Science and Technology Development Plan of Jilin Province, China (Grant No. JJKH20190118KJ)

• Published in: Chinese physics B Vol. 29; no. 8
• Main Authors: Ji, Lanting, Chen, Wei, Gao, Yang, Xu, Yan, Wu, Chi, Wang, Xibin, Yi, Yunji, Li, Baohua, Sun, Xiaoqiang, Zhang, Daming
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.08.2020
• Subjects: electro-optic modulator; graphene; silicon nitride; waveguide
• ISSN: 1674-1056
• DOI: 10.1088/1674-1056/ab943b

Electro-optic modulator is a key component for on-chip optical signal processing. An electro-optic phase modulator based on multilayer graphene embedded in silicon nitride waveguide is demonstrated to fulfill low-power operation. Finite element method is adopted to investigate the interaction enhancement between the graphene flake and the optical mode. The impact of multilayer graphene on the performance of phase modulator is studied comprehensively. Simulation results show that the modulation efficiency improves with the increment of graphene layer number, as well as the modulation length. The 3-dB bandwidth of around 48 GHz is independent of graphene layer number and length. Compared to modulator with two- or four-layer graphene, the six-layer graphene/silicon nitride waveguide modulator can realize π phase shift at a low-power consumption of 14 fJ/bit when the modulation length is 240 μm.