Luyu Wang, Hanke Feng, Liga Bai, Zhouze Zhang, Zhe Ding, Yifan Wu, Linze Li, Dingran Gu, Tianyu Long, Lu Zhang, Xianbin Yu, Zhidong Lyu, Cheng Wang, Baile Chen
Terahertz (THz) communication unlocks massive capacity for future data-intensive networks. While photonics-based THz systems offer broad bandwidths, their reliance on discrete optical assemblies dictates substantial coupling losses and bulky footprints. Achieving complete on-chip integration without degrading the bandwidth or efficiency of discrete optoelectronic components remains a central challenge. Here, we demonstrate an integrated photonic THz transmitter by heterogeneously bonding an InP-based uni-traveling-carrier photodiode (UTC-PD) to a thin-film lithium niobate (TFLN) modulator chip. This architecture successfully merges TFLN's excellent electro-optic response with robust III-V THz generation, featuring an integrated photodiode with a benchmark 3-dB bandwidth of 240 GHz and 0.67 A/W internal responsivity. In sub-THz wireless links, the transmitter delivers 40 Gbit/s at 150 GHz and 32 Gbit/s at 200 GHz using NRZ or PAM4 formats, establishing a scalable pathway for next-generation wireless interconnects.