Generation of Spatiotemporal Vortex Pulses by Simple Diffractive Grating

TL;DR

This paper presents a simple method to generate spatiotemporal vortex pulses using a basic diffractive grating, enabling easier exploration of their dynamics and applications across various wave systems.

Contribution

A novel, straightforward approach to produce spatiotemporal vortex pulses with simple diffractive gratings, bypassing complex equipment.

Findings

Successful generation of vortex pulses on a liquid surface wave platform.

Real-time observation of pulse evolution and dynamics.

Method applicable to various wave systems.

Abstract

Spatiotemporal vortex pulses are wave packets that carry transverse orbital angular momentum, exhibiting exotic structured wavefronts that can twist through space and time. Existing methods to generate these pulses require complex setups like spatial light modulators or computer-optimized structures. Here, we demonstrate a new approach to generate spatiotemporal vortex pulses using just a simple diffractive grating. The key is constructing a phase vortex in frequency-momentum space by leveraging symmetry, resonance, and diffraction. Our approach is applicable to any wave system. We use a liquid surface wave platform to directly demonstrate and observe the real-time generation and evolution of spatiotemporal vortex pulses. This straightforward technique provides opportunities to explore pulse dynamics and potential applications across different disciplines.