Improved focusing with Hypergeometric-Gaussian type-II optical modes

TL;DR

This paper introduces a new family of optical modes called HyGG-II, which have minimal divergence and can generate highly focused light beams suitable for advanced near-field optical applications.

Contribution

The paper presents HyGG-II modes, a novel family of paraxial beams with minimal divergence, enabling the creation of ultra-focused light beams for potential use in near-field optics.

Findings

HyGG-II modes have the lowest divergence among finite power paraxial modes.

HyGG-II modes can generate ultra-narrow light needles after focusing.

Potential applications in high-resolution near-field optics.

Abstract

We present a novel family of paraxial optical beams having a confluent hypergeometric transverse profile, which we name hypergeometric Gauss modes of type-II (HyGG-II). These modes are eigenmodes of the photon orbital angular momentum and they have the lowest beam divergence at waist of HyGG-II among all known finite power families of paraxial modes. We propose to exploit this feature of HyGG-II modes for generating, after suitable focusing, a "light needle" having record properties in terms of size and aspect ratio, possibly useful for near-field optics applications.