Efficient THz sensing with undetected photons using the graphene lasers

Utilizing quantum coherent photons opens up new opportunities in many areas of science and technology. One technological obstacle to this approach nowadays is the low efficiency of creating coherent photons. We propose an efficient solution to the problem by generating coherent photons using the coupled graphene quantum dot (GQD) lasers activated with a short voltage pulse. We illustrate the method by considering the terahertz (THz) sensing with undetected photons. Our simulation results suggest that the nanoscale GQD setup offers attractive advantages compared to the former traditional approaches. They are ({\it i}) generation efficiency is improved by three--four orders of magnitude, ({\it ii}) easier frequency tunability, ({\it iii}) overall simplification of the sensing technique, and ({\it iv}) an immediate control of the signal and idler beam parameters in wide limits just by applying the control gate voltages.