Bidirectional interconversion of microwave and light with diamond nitrogen vacancy center

This study investigates the conversion of microwave signals to optical frequencies and vice versa, utilizing atomic coherence control and gain-based nonlinear optics within a closed-loop quantum system. We implement this method to establish a three-level quantum system based on a nitrogen vacancy center crystal, owing to its exceptional properties. It has been demonstrated that bidirectional interconversion of microwave and light is possible in the closed-loop quantum system via cross-Kerr nonlinearity due to the scattering of the microwave into the light field, in multi-photon resonance condition. Our investigation delves into the underlying mechanisms and demonstrates that significant efficiencies can be achieved through careful engineering of the system parameters. The capability to convert microwave-to-visible and visible-to-microwave frequencies underscores the potential applications of this technology in quantum communications, radio-optical systems, security applications, radar technology and quantum information processing by superconducting circuits.