A low complexity reconstruction approach for optical detection magnetic resonance based diamond NV color center magnetic field measurement

Diamond Nitrogen vacancy (NV) color center-based weak magnetic field detection is a popular topic for quantum sensing. The primary method of NV color center magnetic field measurement is the optical detection magnetic resonance (ODMR) method, including three main steps laser polarization, microwave excitation, and fluorescence signal collection. Then the intensities of the fluorescence signals are outputted as an ODMR curve where the magnetic field parameters can be directly observed. However, microwave excitation requires using a large number of frequencies by scanning the frequencies in a specific range, resulting in high complexity and low efficiency. Less than 50% of the microwave excitations are useful, and the rest works barely help to measure. The reason is that only the resonance peaks contain the magnetic field information, so only the microwave frequencies around the resonance peaks need to be excited. Therefore, we consider exciting only a few frequency microwaves. This paper proposes a random frequency microwave excitation method based on the Lorentz function fitting reconstruction, referred to as the under-sampling reconstruction based ODMR (USR-ODMR). It only excites several microwave frequencies randomly to produce the ODMR curve. The main idea of USR-ODMR is to select proper frequencies from random frequencies by employing the constant false alarm rate-based threshold. At last, a diamond NV color center magnetometer is implemented and tested to obtain ODMR curves. Experimental results show that the USR-ODMR can accurately reconstruct the ODMR curves with much lower complexity than the traditional ODMR method.