Amplitude Structure of Optical Vortices Determines Annihilation Dynamics

TL;DR

This paper investigates how the initial size of optical vortex cores influences their annihilation dynamics, demonstrating that core size affects the speed and possibility of vortex pair annihilation through hydrodynamic principles.

Contribution

It reveals that the initial amplitude structure of optical vortices determines their annihilation behavior, supported by simulations and experiments showing core size impacts vortex dynamics.

Findings

Larger vortex cores annihilate faster when close together.

Smaller cores delay or prevent annihilation due to diffraction effects.

Hydrodynamics governs vortex motion and annihilation processes.

Abstract

We show that annihilation dynamics between oppositely charged optical vortex pairs can be manipulated by the initial size of the vortex cores, consistent with hydrodynamics. When sufficiently close together, vortices with strongly overlapped cores annihilate more quickly than vortices with smaller cores that must wait for diffraction to cause meaningful core overlap. Numerical simulations and experimental measurements for vortices with hyperbolic tangent cores of various initial sizes show that hydrodynamics governs their motion, and reveal distinct phases of vortex recombination; decreasing the core size of an annihilating pair can prevent the annihilation event.