Generation of arbitrary complex quasi-non-diffracting optical patterns

TL;DR

This paper introduces a versatile method for generating quasi-non-diffracting optical beams with nearly arbitrary intensity patterns, expanding the possibilities for applications in optical manipulation and photonics.

Contribution

The authors develop a technique to produce complex quasi-non-diffracting beams with customizable intensity distributions by modifying the angular spectrum, surpassing the limitations of traditional non-diffracting beams.

Findings

Generated diverse spiral and composite patterns.

Beams maintain shape over large distances with tunable diffraction properties.

Optical trapping experiments demonstrate practical utility.

Abstract

Due to their unique ability to maintain an intensity distribution upon propagation, non-diffracting light fields are used extensively in various areas of science, including optical tweezers, nonlinear optics and quantum optics, in applications where complex transverse field distributions are required. However, the number and type of rigorously non-diffracting beams is severely limited because their symmetry is dictated by one of the coordinate system where the Helmholtz equation governing beam propagation is separable. Here, we demonstrate a powerful technique that allows the generation of a rich variety of quasi-non-diffracting optical beams featuring nearly arbitrary intensity distributions in the transverse plane. These can be readily engineered via modifications of the angular spectrum of the beam in order to meet the requirements of particular applications. Such beams are not rigorously non-diffracting but they maintain their shape over large distances, which may be tuned by varying the width of the angular spectrum. We report the generation of unique spiral patterns and patterns involving arbitrary combinations of truncated harmonic, Bessel, Mathieu, or parabolic beams occupying different spatial domains. Optical trapping experiments illustrate the opto-mechanical properties of such beams.