Digital communication link based on THz QCL and THz QWP

Terahertz (THz) technology has attracted a great deal of interest for its unique features and potential applications in many areas. Along with the increasing demand of high bit rate for wireless data transmission and the improvement of material growth and device fabrication, THz communication has become one of the most important fields in the development of future high speed wireless communication systems. The characteristics and the state of the art in THz wireless communication were introduced in this paper. A digital communication link based on terahertz quantum cascade laser (THz QCL) and terahertz quantum well photodetector (THz QWP) was demonstrated. Using direct On-Off-Key (OOK) modulation and direct detection, a pseudorandom non-return-to-zero (NRZ) signal with a bit rate of 1 Mbps was transmitted through the link. The carrier frequency was 3.9 THz, and the link distance was 2.2 m. The limitation and potentiality of the transmission speed for such a system was discussed.