Noise analysis for multi-channel ‘THz Torch’ thermal infrared wireless communications systems

The ‘THz Torch’ concept was recently introduced by the authors for providing secure wireless communications over short distances within the thermal infrared (10–100 THz). Unlike conventional systems, thermal infrared can exploit front-end thermodynamics with engineered blackbody radiation. In this paper, a noise analysis is given for this new form of wireless link, which has the potential to operate up to ∼1 km in range. The mathematical modeling of a short end-to-end link is presented, which integrates thermodynamics into conventional noise power analysis. As expected from the Friis formula for noise, it is found that the noise contribution from the pyroelectric detector dominates intrinsic noise. Measured noise power is compared with calculated results. Our noise analysis can serve as an invaluable tool for the development of thermal infrared systems, accurately characterizing the noise performance of each individual channel and, thus, enables the performance of multichannel ‘THz Torch’ systems to be optimized.