Wireless communications on THz carriers takes shape

High carrier frequencies in the terahertz range 0.1...30 THz are required for wireless data transmission at line rates at or beyond 100 Gbit/s. Here we demonstrate a system with one to three carriers near 237GHz for (75...100) Gbit/s single-polarization transmission over distances of (20...40) m. The narrow-band THz carrier is generated by photomixing of highly stable mode-locked laser lines in a uni-travelling-carrier photodiode. The electrical photodiode output is radiated over a lensed horn antenna. Besides a receiving lensed horn antenna, the receiver comprises monolithic integrated circuits with mixers and amplifiers. This synergetic use of THz photon-ics and electronics ("teratronics") should be scalable to wireless Tbit/s transmission over 1 km. Such a wireless link could bridge the last mile to a subscriber, or could connect two spatially separated fibre gateways.