On-chip spatiotemporal optical vortex generation using an integrated metal-dielectric resonator

TL;DR

This paper theoretically demonstrates how to generate spatiotemporal optical vortex beams on-chip using an integrated metal-dielectric resonator, with potential applications in integrated photonics.

Contribution

It introduces a novel method for on-chip STOV generation via a metal-dielectric structure and derives its vectorial transfer function for this purpose.

Findings

Theoretical model predicts STOV generation upon reflection from the structure.

Numerical simulations confirm the theoretical predictions.

The method enables on-chip manipulation of complex light fields.

Abstract

We theoretically demonstrate the possibility of generating a spatiotemporal optical vortex (STOV) beam in a dielectric slab waveguide. The STOV is generated upon reflection of a spatiotemporal optical pulse from an integrated metal-dielectric structure consisting of metal strips "buried" in the waveguide. For describing the interaction of the incident pulse with the integrated structure, we derive its "vectorial" spatiotemporal transfer function (TF) describing the transformation of the electromagnetic field components of the incident pulse. We show that if the TF of the structure corresponds to the TF of a spatiotemporal differentiator with a $\pi/2$ phase difference between the terms describing temporal and spatial differentiation, then the envelope of the reflected pulse will contain an STOV in all nonzero components of the electromagnetic field. The obtained theoretical results are in good agreement with the results of rigorous numerical simulation of the STOV generation using a three-strip metal-dielectric integrated structure. We believe that the presented results pave the way for the research and application of STOV beams in the on-chip geometry.