Volumetric incorporation of NV diamond emitters in nanostructured F2 glass magneto-optical fiber probes

TL;DR

This paper introduces a novel method for embedding nanodiamonds with nitrogen-vacancy centers directly into the core of glass fibers, enabling scalable magnetic sensing with integrated diamond emitters.

Contribution

The authors develop a new fabrication technique for integrating nanodiamonds into fiber cores using nanostructurization and stacking of soft glass canes, allowing precise control over nanodiamond distribution.

Findings

Nanodiamonds are uniformly distributed in the fiber core without significant agglomeration.

The fiber exhibits red fluorescence along its length, indicating successful integration.

Magnetic sensitivity is demonstrated through optically detected magnetic resonance measurements.

Abstract

Integration of optically-active nanodiamonds with glass fibers is a powerful method of scaling of diamond magnetic sensing functionality. We propose a novel approach for integration of nanodiamonds containing nitrogen-vacancy centers directly into the fiber core. The core is fabricated using nanostructurization, that is by stacking the preform from 790 soft glass canes, drawn from a single rod dip-coated with nanodiamonds suspended in isopropyl alcohol. This enables manual control over distribution of nanoscale features, here - the nanodiamonds across and along the fiber core. We verify this by mapping the nanodiamond distribution in the core using confocal microscopy. The nanodiamonds are separated longitudinally either by 15 microns or 24 microns, while in the transverse plane separation of approximately 1 micron is observed, corresponding to the individual cane diameter in the final fiber, without significant agglomeration. Filtered, red fluorescence is observed with naked eye uniformly along the fiber. Its magnetic sensitivity is confirmed by in optically detected magnetic resonance recorded with a coiled, 60-cm-long fiber sample with readout contrast limited mainly by microwave antenna coverage. NV fluorescence intensity in 0 to 35 mT magnetic field is also demonstrated, allowing magnetometry applications with a large B-field dynamic range in absence of microwaves.