Control of vortex orientation of ultrashort optical pulses using spatial chirp

TL;DR

This paper demonstrates how introducing spatial chirp into vortex pulses allows control over the orientation of the phase singularity, enabling arbitrary alignment between longitudinal and transverse directions.

Contribution

It provides analytical expressions for vortex pulses with arbitrary topological charge and describes how spatial chirp can manipulate vortex orientation during propagation.

Findings

Spatial chirp enables arbitrary vortex orientation control.

Analytical expressions valid at any propagation distance.

Vortex line orientation can be tuned between longitudinal and transverse.

Abstract

Introducing a spatial chirp into a pulse with a longitudinal vortex, such as a standard pulsed Laguerre-Gauss beam, results in a vortex pulse with an arbitrary orientation of the line phase singularity between longitudinal and transverse, depending on the amount of chirp. Analytical expressions are given for such pulses with arbitrary topological charge valid at any propagation distance.