Nitrogen-vacancy centers in diamond for instantaneous spectral analysis in the radiofrequency domain up to 18 GHz

Detection and spectroscopy of microwave (> GHz) signals is of pivotal importance for key areas of modern technology, including wireless communication, radar, navigation and medical imaging. Here we demonstrate a real-time spectrum analysis of microwave signals using nitrogen-vacancy (NV) centers in diamond. By monitoring electron spin dependent fluorescence of NV centers under a continuous illumination, we managed to detect microwave signal with a 1 MHz resolution spatial resolution, a upper frequency limit of 18 GHz and a 1 ms temporal resolution.