Optoelectronic based Quantum Radar: Entanglement Sustainability Improving at High Temperature

In this study, the main focus is laid on the design of the optoelectronic quantum illumination system to enhance the system performance, such as operation at high temperature and confinement of the thermally excited photons. The optomechanical based quantum illumination system has wieldy been studied, and the results showed that operation at high temperature is so crucial to preserve the entanglement between modes. The main problem is that the mechanical part has to operate with a low frequency with which a large number of thermally excited photons are generated and worsened the entanglement. To solve this problem, we focus on replacing the mechanical part with the optoelectronic components. In this system, the optical cavity is coupled to the microwave cavity through a Varactor diode excited by a photodetector. The photodetector is excited by the optical cavity modes and drives the current flow as a function of incident light drives the Varactor diode at which the voltage drop is a function of current generated by the photodetector. To engineer the system, the effect of some parameters is investigated. One of the critical parameters is the microwave cavity to the photodetector coupling factor. Our results indicate that this coupling factor induces a significant difference in the new design as compared to the optomechanical quantum illumination system. At some specific values of the coupling factor, the modes remained completely entangled up to 5.5 K and partially entangled around 50 K.