Advances in High-Speed Data Transmission: Heterogeneous Integration of Thin-Film Lithium Niobate Electro-Optic Modulators

Release time：

2025-08-15

Heterogeneous integration solutions for photonic circuits can fully leverage the advantages of different material platforms.Recently, the research teams led by Prof. Yan Cai and Prof. Xin Ou from the Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, successfully integrated high-quality lithium niobate (LiNbO₃) thin films onto a 6-inch patterned silicon nitride (SiN) wafer using a versatile 'ion-slicing' technique. Leveraging wafer-scale processing, they developed a heterogeneously integrated thin-film LiNbO₃ electro-optic modulator with high-speed data transmission capability. In this scheme, SiN and LiNbO₃ form a hybrid waveguide structure, eliminating the need for LiNbO₃ etching and simplifying the fabrication process.

The research team designed and experimentally demonstrated a high-performance silicon nitride-thin-film lithium niobate (SiN-LNOI) heterogeneously integrated Mach-Zehnder electro-optic modulator, fabricated via a full wafer-scale process and capable of simultaneous operation in both O-band and C-band.Using the versatile ion-slicing technique, the team achieved heterogeneous integration of 6-inch thin-film lithium niobate with patterned 6-inch SiN wafers.To avoid etching the thin-film lithium niobate, all device patterns were implemented in the SiN layer.The fabricated device demonstrated a 3-dB electro-optic bandwidth exceeding 110 GHz in the C-band, supporting data rates up to 260 Gbit/s in PAM-4 modulation format.The heterogeneously integrated electro-optic modulator exhibited VπL values of 2.15 V·cm at 1310 nm and 2.7 V·cm at 1550 nm.This work developed a heterogeneously integrated SiN/TFLN modulator with low insertion loss, high electro-optic bandwidth, and high data rate through wafer-scale fabrication.

This work not only explores full wafer-scale fabrication of heterogeneously integrated thin-film LiNbO₃ electro-optic modulators, but also lays the foundation for future mass production of wafer-level Si-photonics/LNOI integration.

Recently, these findings were published online in Laser & Photonics Reviews under the title 'Hybrid Silicon Nitride/Lithium Niobate Electro-Optical Modulator with Wide Optical Bandwidth and High RF Bandwidth Based on Ion-cut Wafer-level Bonding Technology'.

This research was supported by the National Key Laboratory of Integrated Circuit Materials and other independent research projects.