High-resolution wide-field magnetic imaging with sparse sampling using nitrogen-vacancy centers

TL;DR

This paper introduces a sparse-sampling method combined with Bayesian estimation to enable high-resolution wide-field magnetic imaging using NV centers, significantly reducing measurement time while maintaining image quality.

Contribution

The authors develop a novel sparse-sampling strategy and Bayesian reconstruction framework for NV-based magnetic imaging, allowing high-resolution images from minimal measurements.

Findings

Reconstructed 10,000-pixel images from only 25 samples with high SSIM.

Optimized dynamical-decoupling sequences doubled magnetic-field sensitivity.

Sampling pattern and density critically influence reconstruction accuracy.

Abstract

Nitrogen-vacancy (NV) centers in diamond enable quantitative magnetic imaging, yet practical implementations must balance spatial resolution against acquisition time (and thus per-pixel sensitivity). Single-NV scanning magnetometry achieves genuine nanoscale resolution, nonetheless requires typically a slow pixel-by-pixel acquisition. Meanwhile, wide-field NV-ensemble microscopy provides parallel readout over a large field of view, however is jointly limited by the optical diffraction limit and the sensor-sample standoff. Here, we present a sparse-sampling strategy for reconstructing high-resolution wide-field images from only a small number of measurements. Using simulated NV-ensemble detection of ac magnetic fields, we show that a mean-adjusted Bayesian estimation (MABE) framework can reconstruct 10000-pixel images from only 25 sampling points, achieving SSIM values exceeding 0.999 for representative smooth field distributions, while optimized dynamical-decoupling pulse sequences yield an approximately twofold improvement in magnetic-field sensitivity. The method further clarifies how sampling patterns and sampling density affect reconstruction accuracy and suggests a route toward faster and more scalable magnetic-imaging architectures that may extend to point-scanning NV sensors and other magnetometry platforms, such as SQUIDs, Hall probes, and magnetic tunnel junctions.