Super-resolution Optical Near-field EM for bio- and materials science

TL;DR

This paper introduces Optical Near-field Electron Microscopy (ONEM), a novel super-resolution imaging technique that achieves nanometer spatial and sub-second temporal resolution without damaging samples, applicable across biology, electrochemistry, and nanophotonics.

Contribution

The paper presents ONEM, a new method converting optical near-field patterns into photoelectron emission for non-invasive, high-resolution imaging in vacuum and liquid environments.

Findings

Achieves 31 nm spatial resolution and sub-second temporal resolution.

Successfully visualizes live bacteria in liquid with 3D orientation contrast.

Captures real-time electrodeposition of copper nanoclusters.

Abstract

Microscopy has been key to tremendous advances in science, technology, and medicine, revealing structure and dynamics across time and length scales. However, combining high spatial and temporal resolution in a non-invasive, label-free imaging technique remains a central challenge in microscopy. Here, we introduce Optical Near-field Electron Microscopy (ONEM), a method that converts optical near-field intensity patterns into photoelectron emission, enabling nanometer-scale imaging using low-energy electron microscopy. ONEM achieves 31 nm spatial and sub-second temporal resolution without exposing the sample to electrons, preserving structural and functional integrity. We demonstrate ONEM across three distinct domains: imaging polarization-dependent plasmon modes in metal nanostructures; visualizing live Escherichia coli in liquid with orientation-resolved contrast in 3D; and capturing real-time electrodeposition of copper nanoclusters from solution. These results establish ONEM as a versatile platform for damage-free super-resolution imaging of interface dynamics in both vacuum and liquid, with broad implications for biology, electrochemistry, and nanophotonics.