Ultra-low cost ubiquitous THz security systems

This paper introduces an ultra-low cost THz system for ubiquitous security applications operating in the far/mid-infrared parts of the electromagnetic spectrum. By extending the recently reported “THz torch” concept, this technology can be used to implement frequency division multiplexing (FDM) and frequency-hopping spread spectrum techniques for secure RFID tag and smart key fob applications. Results from a “THz torch” FDM wireless link are presented for the first time. Here, an ultra-low cost 4-channel FDM system has been demonstrated with an end-to-end bit rate of more than 40 bps. This represents an eight-fold increase in bit rate, and over twice the distance, when compared to previously reported results.