Portable Diamond NV Magnetometer Head Integrated With 520 nm Diode Laser

The integrated diamond nitrogen vacancy (NV) magnetometer has attracted considerable attention in recent years and presents high potential for its use in magnetic field detection in fields such as aerospace, medical, and agriculture. A laser with a large volume seriously hampers the integration and performance of magnetometers. To solve this problem, we proposed a 520-nm laser diode with an integrated NV magnetometer. The 520-nm laser diode has a high excitation efficiency and good performance with a small size. We introduced the key steps of designing an integrated magnetometer head and tested the performance, a magnetic field sensitivity of $20.77\,\,{n}T\,\,\cdot \,\,Hz^{-1/2}$ , and a shot noise sensitivity of $1.43\,\,{n}T\,\,\cdot \,\,Hz^{-1/2}$ . The measurable magnetic field range is from −107 to $107 ~\mu \text{T}$ , the system bandwidth is 15 Hz at the laser power of 10 mW, and the magnetic field conversion coefficient is 16.88 V/T. Thus, this paper provides a new method to minimise the light source volume and integrate it with a NV magnetometer.