An integrated magnetometry platform with stackable waveguide-assisted detection channels for sensing arrays

TL;DR

This paper introduces a novel integrated diamond-based magnetometry platform with waveguide-assisted detection channels, enabling non-invasive, high-sensitivity magnetic sensing suitable for biological applications and scalable sensor arrays.

Contribution

The work presents a new architecture combining NV-centers near the surface with femtosecond-laser-written waveguides for efficient, non-invasive magnetic sensing and array integration.

Findings

Verified coupling efficiency between NV-centers and waveguides

Demonstrated magnetic resonance detection through waveguides

Performed initial magnetic field and temperature sensing experiments

Abstract

The negatively-charged NV$^-$-center in diamond has shown great success in nanoscale, high-sensitivity magnetometry. Efficient fluorescence detection is crucial for improving the sensitivity. Furthermore, integrated devices enable practicable sensors. Here, we present a novel architecture which allows us to create NV$^-$-centers a few nanometers below the diamond surface, and at the same time in the mode field maximum of femtosecond-laser-written type-II waveguides. We experimentally verify the coupling efficiency, showcase the detection of magnetic resonance signals through the waveguides and perform first proof-of-principle experiments in magnetic field and temperature sensing. The sensing task can be operated via the waveguide without direct light illumination through the sample, which marks an important step for magnetometry in biological systems which are fragile to light. In the future, our approach will enable the development of two-dimensional sensing arrays facilitating spatially and temporally correlated magnetometry.