Spatiotemporal Optical Vortices: Toward Tailoring Orbital Angular Momentum of Light in Full Space-Time

Abstract

Longitudinal orbital angular momentum (OAM) is a fundamental property of light that has been the subject of extensive research and applied to diverse important applications, such as optical tweezers, super-resolution imaging, and optical information processing. Recently, photons have been observed to possess transverse OAM, where the OAM vector is orthogonal to the direction of light propagation. As the carrier for this unique OAM, the spatiotemporal (ST) optical vortex has attracted considerable interest. Here, we provide a general overview of recent experimental and theoretical advances on such vortices, presenting their synthesis and measurement strategies, highlighting their nontrivial properties in linear propagation and interaction with nonlinear matter, and discussing the possible future trends and challenges.

Metasurface for Engineering Superimposed Ince‐Gaussian Beams

“…[28,29] Recently, metasurfaces have been utilized to generate various structured beams, e.g., polarization knots, [30,31] composite vortex beams, [32,33] grafted vector vortices, [34,35] orbital angular momentum (OAM) holograms, [36,37] Airy beams, [38,39] and spatiotemporal light fields. [40,41] To tackle the fundamental and technical challenges in the generation of IGBs, we propose and experimentally demonstrate a compact metasurface platform for generating and manipulating IGBs. For the first time, a single metasurface is used to generate superimposed IGBs through the superposition of even and odd Ince modes without relying on a complicated optical setup.…”

Optical Twisted Phase Strips

“…15 The selected polarization distribution in a threedimensional (3D) vector light field forms framed knots, 16 which can be used as information carriers taking the advantage of the braid representation of knots. 17 With the development of modern beam shaping techniques, the control of both the time and space domain allows the construction of spatiotemporal light fields, 18,19 which exhibits novel photophysical properties such as the transverse orbital angular momentum of the photon. 20 With the addition of conformal mapping, 21,22 spatiotemporal toroidal vortex has been demonstrated recently, 23 which is a dynamic optical topological structure.…”

“…With the development of modern beam shaping techniques, the control of both the time and space domain allows the construction of spatiotemporal light fields, , which exhibits novel photophysical properties such as the transverse orbital angular momentum of the photon . With the addition of conformal mapping, , spatiotemporal toroidal vortex has been demonstrated recently, which is a dynamic optical topological structure.…”