Advanced Electrode Design for Low-Voltage High-Speed Thin-Film Lithium Niobate Modulators

作者：Xingrui Huang, Yang Liu, Zezheng Li, Huan Guan, Qingquan Wei, Zhiguo Yu, Zhiyong Li · 发表于：IEEE photonics journal · 年份：2021 · DOI：10.1109/jphot.2021.3066159 · 被引用次数：32 · 研究领域：Photonic and Optical Devices、Photorefractive and Nonlinear Optics、Advanced Fiber Laser Technologies

In this paper, we present a novel transmission line architecture in thin-film lithium niobate (TFLN) platforms to improve the velocity match between the microwave and the optical wave. Compared to conventional coplanar waveguide (CPW), the microwave index (nm) of the proposed slotted electrodes can be optimized from 2.1 to 3 while maintaining the high modulation efficiency and 50-Ω impedance match. Equivalent-circuit model analysis and finite-element simulation are performed. The simulated half-wave voltage (Vπ) of 1.2 V and E-O modulation bandwidth greater than 80 GHz is obtained for a 2-cm-long modulator. By utilizing the slotted slow-wave electrode, TFLN Mach-Zehnder modulators with CMOS-compatible operating voltage and 3-dB modulation bandwidth greater than 100 GHz are potentialized.