High-Modulation-Efficiency Lithium Niobate Electro-Optic Modulator Based on Sunken Dual-Layer Electrode

Electro-optic modulators with high bandwidth, high modulation efficiency, and low loss play a crucial role in many fields, such as artificial intelligence, analog communications, and satellite data links. The modulation efficiency and loss, which are related to the chip size and integration, are important parameters for modulators. However, the modulation efficiency and optical loss of electro-optic modulators are interrelated in general. In this study, an improved scheme combining sunken electrodes and dual-layer capacitance-loaded electrodes is exhibited, improving the constraint between the modulation efficiency and optical loss of thin-film lithium niobate electro-optic modulators by enhancing the electric field effect. An electro-optic modulator with a high bandwidth (>60 GHz), low optical loss (0.14 dB/cm), and low half-wave voltage–length product (1.52 V·cm) has been realized using finite element analysis software.