Open AccessUltra-efficient and fully isotropic monolithic microring modulators in a thin-film lithium niobate photonics platform
Author(s) -
Mehdi N. Bahadori,
Yansong Yang,
Ahmed E. Hassanien,
Lynford L. Goddard,
Songbin Gong
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.400413
Subject(s) - lithium niobate , materials science , optics , optoelectronics , photonics , extinction ratio , optical modulator , waveguide , photonic integrated circuit , modulation (music) , phase modulation , physics , phase noise , acoustics , wavelength
The large electro-optic coefficient, r 33 , of thin-film lithium niobate (LN) on insulator makes it an excellent material platform for high-efficiency optical modulators. Using the fundamental transverse magnetic optical mode in Z-cut LN enables isotropic in-plane devices; however, realizing a strong vertical electric field to capitalize on r 33 has been challenging. Here we present a symmetric electrode configuration to boost the vertical field strength inside a fully-etched single-mode LN waveguide. We use this design paradigm to demonstrate an ultra-compact fully isotropic microring modulator with a high electro-optic tuning efficiency of 9 pm/V, extinction ratio of 20 dB, and modulation bandwidth beyond 28 GHz. Under quasi-static operation, the tuning efficiency of the modulator reaches 20 pm/V. Fast, efficient, high-contrast modulation will be critical in future optical communication systems while large quasi-static efficiency will enable post-fabrication trimming, thermal compensation, and even complete reconfiguration of microring-based sensor arrays and photonic integrated circuits.