A Broadband Lithium Tantalate-on-Silicon Nitride Heterogeneous Modulator for Optical and Terahertz Communications and Radar Sensing

Abstract Photonic integrated circuits (PICs) have driven advances in optical interconnect, wireless communications, seamless sensing, etc. Among various components of PICs, electro-optic modulators serve as the critical bridge between the electronic and optical domains, acting as the cornerstone of these systems. To address the ultra-broadband demands of next-generation information systems while enabling heterogeneous integration with other functional components, we present a high-performance thin-film lithium tantalate-on-silicon nitride heterogeneous Mach-Zehnder modulator (MZM), fabricated via micro-transfer printing. The MZMs show an insertion loss of 1.0 dB, an electro-optic bandwidth exceeding 110 GHz, and a power drift of ~0.3 dB over 72 h at quadrature bias. We employ the modulator for three typical scenarios in the applications of optical communications, full photonic terahertz wireless communication, and radar sensing. Using the MZM, we achieve optical data transmission rates beyond 375 Gbps, a record of 148 Gbps for wireless communications in the D-Band, and a range resolution of 1.2 cm with measured errors below 2 mm in the W-Band. These results pave the way for scalable, high-performance, cross-domain photonic chips for next-generation information networks.