Hybrid Silicon Nitride/Lithium Niobate Electro‐Optical Modulator with Wide Optical Bandwidth and High RF Bandwidth Based on Ion‐Cut Wafer‐Level Bonding Technology

Abstract Heterogeneous integration solutions for photonics circuits exploit the advantages of different platforms. Here, the design, fabrication, and characterization of a high‐performance heterogeneous silicon nitride (SiN)/thin film lithium niobate (TFLN) electro‐optic Mach–Zehnder modulator are shown. This work is based on wafer‐scale direct bonding, followed by ion‐cut technology and wafer‐scale fabrication. All the optical control is achieved in SiN layer, and the lithium niobate is etchless. Edge couplers (ECs) are integrated as input and output ports, and the modulator shows a total insertion loss of 11.6 dB, a broadband electro‐optic response with 3 dB bandwidth beyond 110 GHz at C‐band, and supports 180 Gbit/s data transmission for NRZ format and 260 Gbit/s data transmission for PAM‐4 format. The device also shows a good modulation capability from 1260 to 1640 nm due to the wavelength insensitivity of the hybrid ECs. Such high‐performance integrated EOMs based on fully wafer‐scale fabrication may lay the foundations for the mass production of a multi‐material integration platform in the future.