# Super-Resolution Fluorescence Imaging of Carbon Nanotubes Using a Nonlinear Excitonic Process

## TL;DR

This paper demonstrates super-resolution imaging of carbon nanotubes by exploiting nonlinear excitonic processes, specifically exciton-exciton annihilation, achieving resolution beyond the diffraction limit through experimental and simulation methods.

## Contribution

It introduces a novel imaging technique using nonlinear excitonic annihilation in nanotubes for super-resolution, with quantitative analysis and a new method for further image sharpening.

## Key findings

- Resolution beyond diffraction limit achieved
- Quantitative analysis of annihilation efficiency
- Enhanced image sharpness via cubic dependence method

## Abstract

Highly efficient exciton-exciton annihilation process unique to one-dimensional systems is utilized for super-resolution imaging of air-suspended carbon nanotubes. Through the comparison of fluorescence signals in linear and sublinear regimes at different excitation powers, we extract the efficiency of the annihilation processes using conventional confocal microscopy. Spatial images of the annihilation rate of the excitons have resolution beyond the diffraction limit. We investigate excitation power dependence of the annihilation processes by experiment and Monte Carlo simulation, and the resolution improvement of the annihilation images can be quantitatively explained by the superlinearity of the annihilation process. We have also developed another method in which the cubic dependence of the annihilation rate on exciton density is utilized to achieve further sharpening of single nanotube images.