# Effects of orbital angular momentum on few-cycle pulse shape: Coupling between the temporal and angular momentum degrees of freedom

## TL;DR

This paper investigates how orbital angular momentum (OAM) influences the shape of few-cycle pulses, revealing that high OAM significantly lengthens pulse duration and enhances spatiotemporal coupling, impacting optical communication and attosecond pulse generation.

## Contribution

It introduces the coupling between OAM and temporal degrees of freedom in pulsed beams and analyzes its effects on pulse duration and spatiotemporal properties.

## Key findings

- High OAM increases pulse duration significantly.
- OAM-temporal coupling effects are unavoidable.
- Coupling impacts applications like optical communications and attosecond pulses.

## Abstract

We describe the coupling between orbital angular momentum (OAM) and temporal degrees of freedom in pulsed Laguerre-Gauss beams. The effects of this coupling are to increase significantly the duration of few-cycle pulses when the OAM carried by the pulse is large, and to enhance spatiotemporal couplings. Contrary to other detrimental but retrievable effects such as spatial, group velocity and topological charge dispersions in these pulses, OAM-temporal coupling effects are unavoidable, and have therefore an impact in applications such as OAM-based optical communications, or in the generation of vortex-carrying attosecond pulses.