# Reflection confocal nanoscopy using a super-oscillatory lens

## TL;DR

This paper introduces a reflection confocal nanoscope utilizing a super-oscillatory lens to achieve super-resolution imaging of reflective objects, overcoming previous limitations related to sidelobes and efficiency.

## Contribution

The authors develop a novel reflection confocal nanoscope that relays SOL patterns onto objects, enabling high-resolution imaging of reflective surfaces with improved contrast.

## Key findings

- Achieved 330 nm resolution with a 632.8 nm wavelength.
- Demonstrated enhanced contrast over traditional laser confocal microscopes.
- Identified performance degradation with larger objects.

## Abstract

A Superoscillatory lens (SOL) is known to produce a sub-diffraction hotspot which is useful for high-resolution imaging. However, high-energy rings called sidelobes coexist with the central hotspot. Additionally, SOLs have not yet been directly used to image reflective objects due to low efficiency and poor imaging properties. We propose a novel reflection confocal nanoscope which mitigates these issues by relaying the SOL intensity pattern onto the object and use conventional optics for detection. We experimentally demonstrate super-resolution by imaging double bars with 330 nm separation using a 632.8 nm excitation and a 0.95 NA objective. We also discuss the enhanced contrast properties of the SOL nanoscope against a laser confocal microscope, and the degradation of performance while imaging large objects.