Compact All‐Optical Quantum Sensor Device Based on Nitrogen Vacancy Centers in Diamond

Abstract

An integrated magnetic sensor is designed and tested that utilizes the negatively charged nitrogen vacancy centers (NVC) in diamond as a magnetic field‐sensitive quantum material, which is accessed and readout solely optically. The compact sensor device features a side length of 10 mm and includes a small HPHT diamond slab, light‐emitting diode (LED) for excitation, and integrated photodiodes. A microwave‐free approach is used. With the device, DC sensitivity to magnetic fields of 49 nA mT−1 in the range of 5–50 mT is achieved. The sensor device is also capable of detecting very small magnetic fields: Magnetic field dependencies at very low flux densities in the μT range (zero‐magnetic field) show a characteristic fluorescence behavior revealing a sensitivity of 4.8 pA μT−1. Additionally, a ray‐tracing model is applied, to identify loss mechanisms in the setup. Using this device, an ultracompact, reliable, and industry‐ready package is made available for sensor developments in industry and academia.

Compact and Fully Integrated LED Quantum Sensor Based on NV Centers in Diamond

“…NV centers can also be used to measure temperatures [9][10][11][12], electric fields [13] and there are also applications in the field of quantum computing [14,15]. Other magnetic sensing protocols using the NV center include an all-optical approach using spin mixing in the NV ground state [16][17][18] or measurement of the infrared absorption of the infrared transition with near shot-noise limited sensitivity [19]. As they are a solid-state system in diamond, the sensors can be operated at room temperature.…”