Photonically generated simultaneous multi-band terahertz communication system

Terahertz (THz) wireless communication has emerged as a promising technology for future beyond-6G networks due to its abundant bandwidth resources. However, most experimental THz demonstrations to date are limited to single-band and point-to-point links, which limit their applications in practical multi-user wireless networks. In this work, we demonstrate the first photonically generated simultaneous multi-band THz communication system employing a single transmitter and two independent receivers. A custom-designed uni-travelling-carrier photodiode (UTC-PD)-integrated slot antenna is used as a broadband THz transmitter, enabling the simultaneous generation of THz signals in two industry-standard rectangular waveguide bands: the WR-5.1 band at 144 GHz for separate-reception links and 155 GHz for simultaneous-reception links, and the WR-3.4 band at 222 GHz. Independent photonically pumped WR-5.1 and electronically pumped WR-3.4 receivers are used to receive their respective band signals, either separately or simultaneously. For separate-receiving links, maximum data rates of 80 Gbit/s and 15 Gbit/s are achieved in the WR-5.1 and WR-3.4 bands, respectively. Under simultaneous transmission and reception, adjustment of the THz carrier frequency and transmitted THz power is further investigated. This enables balanced multi-band performance, achieving a data rate of 10 Gbit/s in both bands, and demonstrates the inherent flexibility and adaptability of photonically generated THz systems. These results highlight the potential of photonic THz technology for future multi-band, multi-user wireless access networks.