The authors examine a resonant tunnelling diode (RTD)-based wireless transceiver system in conjunction with radio-over-fibre (RoF) and identify the performance limiting factors. Ultra high-definition television 4K-video over 1 km fibre and 15 cm wireless is demonstrated. In addition error-free data transmission up to 11 Gbit/s over 1 km fibre and 10 cm wireless is also presented. Eye-diagram and jitter results for laboratory RoF equipment show the performance is not degraded with respect to an RTD-only system, and that RoF-RTD is considered promising and complementary technologies.

A hollow metallic waveguide-input resonant tunnelling diode threeterminal mixer device based on a photonic-crystal platform for terahertz (THz) communication applications is presented. Coherent detection was successfully demonstrated, with an increase in the sensitivity of >30 dB compared with that of direct detection. Error-free communications with a data rate >10 Gbit/s at 0.3 THz using the developed device as a coherent THz receiver are achieved.

The authors present an expanded porous polytetrafluoroethylene terahertz fibre transmission link using resonant tunnelling diodes integrated with photonic-crystal waveguides as a transmitter and a receiver. The measured coupling efficiency between the terahertz fibre and the photonic-crystal waveguide integrated with a silicon tapered coupler is ∼30% with a 3 dB bandwidth of 50 GHz at the 0.3 THz band. Error-free 10 Gbit/s transmission and uncompressed 4 K high-definition video transmission have been successfully demonstrated using 1 m-long terahertz fibre.