Topologically protected generation of spatiotemporal optical vortices with nonlocal spatial-mirror-symmetry-breaking metasurface

Abstract

Recently nonlocal spatial-mirror-symmetry-breaking metasurfaces have been proposed to generate spatiotemporal optical vortices (STOVs), which carry transverse orbital angular momenta. Here we investigate the topological property of the STOV generator and show that spatial mirror symmetry breaking introduces a synthetic parameter dimension associated with the metasurface geometry. Furthermore, we demonstrate that there are well-defined vortices emerging with the synthetic parameter dimension, which can topologically protect the STOV generation robustly against structural perturbations and disorders. Since the vortices are always `created' or `annihilated' together in pairs of opposite charges in the $k_x-\omega$ domain, the total topological charge of these vortices is a conserved quantity. Our studies not only provide a new topological perspective for STOV generation but also lay a solid foundation for potential applications of STOV metasurfaces integrated with other optoelectronic devices, because of their robust immunity to fabrication defects.

References in corpus (13)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Topological Photonics
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Visualization of higher-order topological insulating phases in two-dimensional dielectric photonic crystals
• Nonlinear control of PT-symmetry and non-Hermitian topological states
• Spatio-temporal vortex beams and angular momentum
• Roadmap on spatiotemporal light fields
• Second-harmonic generation and the conservation of spatiotemporal orbital angular momentum of light
• Quantum interference of topological states of light
• Controlling Photon Transverse Orbital Angular Momentum in High Harmonic Generation

Cited by in corpus (2)

• Observation of acoustic spatiotemporal vortices
• Spatio-temporal optical vortices: principles of description and basic properties