High resolution imaging with anomalous saturated excitation

TL;DR

This paper investigates the anomalous saturating fluorescence effect of nitrogen vacancy centers in diamond, demonstrating a method to enhance spatial resolution in optical imaging by exploiting nonlinear fluorescence behavior.

Contribution

The study introduces a differential excitation protocol that improves imaging resolution by approximately 1.6 times using simple setup and data processing techniques.

Findings

Fluorescence reduction observed at high laser power

Spatial frequency distribution of fluorescence is altered

Resolution enhancement achieved with differential excitation

Abstract

The nonlinear fluorescence emission has been widely applied for the high spatial resolution optical imaging. Here, we studied the fluorescence anomalous saturating effect of the nitrogen vacancy defect in diamond. The fluorescence reduction was observed with high power laser excitation. It increased the nonlinearity of the fluorescence emission, and changed the spatial frequency distribution of the fluorescence image. We used a differential excitation protocol to extract the high spatial frequency information. By modulating the excitation laser's power, the spatial resolution of imaging was improved approximate 1.6 times in comparison with the confocal microscopy. Due to the simplicity of the experimental setup and data processing, we expect this method can be used for improving the spatial resolution of sensing and biological labeling with the defects in solids.