Superresolution technique beyond the diffraction limit under a structured beam via different optical nanostructures

TL;DR

This paper demonstrates a superresolution technique surpassing the diffraction limit using structured optical nanostructures and twisted beams, achieving a near-field focal spot of 27 nm for enhanced nanophotonic applications.

Contribution

It introduces a novel superresolution method employing twisted Gaussian beams with nanostructures, improving resolution beyond traditional solid immersion lenses.

Findings

Achieved a near-field focal spot of 27 nm FWHM.

Numerical simulations confirm tolerance to fabrication variations.

Potential applications in high-resolution quantum technology scanning.

Abstract

To overcome the limit of diffraction while achieving the superresolution technique, solid immersion lenses are the key optical elements for data storage and nanophotonics applications. Recent demonstrations have shown how different nanostructures (such as elliptical SILs) are used in diverse fields of increasing resolution in the presence of a structured Gaussian beam. By applying twisted beams such as angular momentum beams (Laguerre- Gaussian) and spatial higher-order Gaussian beams (Hermite- Gauss), we can attain a sharp (FWHM = 27 nm) near-field focal spot pattern, which is considerably better than the conventional macroscopic SIL. By numerical simulations, tolerance has been confirmed with a slight variation in beam size and geometrical modification to make the model compatible with fabrication errors. This narrow bandwidth intensity distribution can be utilized for scanning the sample with higher resolution, especially in the field of quantum technology.