Temporal filtered quantum sensing with the nitrogen-vacancy center in diamond

TL;DR

This paper presents a method using pulsed laser excitation and time gating to suppress background fluorescence, significantly improving the sensitivity and speed of nitrogen-vacancy center-based quantum sensors in high-background environments like bioimaging.

Contribution

It introduces an analytical and experimental approach combining pulsed laser excitation with time gating to enhance NV quantum sensing performance in challenging environments.

Findings

Up to 4x increase in signal-to-noise ratio (SNR)

16x reduction in measurement time

Effective background suppression in bioimaging applications

Abstract

Nitrogen vacancy centers in diamond are among the leading solid state quantum platforms, offering exceptional spatial resolution and sensitivity for applications such as magnetic field sensing, thermometry, and bioimaging. However, in high background environments,such as those encountered in in vitro diagnostics, the performance of NV based sensors can be compromised by strong background fluorescence, particularly from substrates such as nitrocellulose. In this work, we analytically and experimentally investigate the use of pulsed laser excitation combined with time gating techniques to suppress background fluorescence and enhance the signal to noise ratio in NV based quantum sensing, with an emphasis on spin enhanced biosensing. Through experimental studies using mixed ensembles of silicon vacancy and NV centers in bulk diamond, as well as fluorescent nanodiamonds on NC substrates, we demonstrate significant improvements in NV spin resonance visibility, demonstrated by an increase of the SNR by up to 4x, and a resulting measurement time reduction by 16x. The presented technique and results here can help significantly increase the readout efficiency and speed in future applications of NV centers in high background environments, such as in IVD, where the NV centers are used as a fluorescent label for biomolecules.