Simultaneous Identification of Multiple Microwave Signals in 313-MHz Continuous Bandwidth Using Nitrogen-Vacancy Centers in Diamond

The efficient and reliable detection of microwave signals is a key element of the breakthrough in new-generation communication technology. In this article, we proposed an approach for the simultaneous identification of multiple microwave signals in a continuous frequency range based on the spectral hole-burning effect of nitrogen-vacancy (NV) centers. The protocol combines the quantum wide-field imaging method with magnetic gradient means, breaking the narrowband and discrete detection limitations of conventional optically detected magnetic resonance (ODMR) techniques. The frequencies of multiple microwave signals can be accurately decoupled by locating the relevant gaps on resonance frequency curves. Meanwhile, the effects induced by fixed-frequency signals with different powers on the resonance frequency curves were systematically analyzed. The experimental results indicated that the system realized a multiple-frequency resolution of 1 MHz and a minimum detectable power of 1 mW over a continuous bandwidth of 313-MHz. This proposal is capable of real-time and simultaneous detection of multiple microwave signals, which remarkably improves the utilization efficiency of spectrum resources.