Topologically Structured Waves

Topological structures and singularities of waves provide a number of nontrivial phenomena and additional functionalities as compared to a single plane wave.  Topological waves underpin modern photonics, yet they are equally important for quantum matter waves, acoustics, water waves, etc.

Featured works:

B. Wang, Z. Che, C. Cheng, C. Tong, L. Shi*, Y. Shen*, K. Y. Bliokh*, J. Zi*, "Topological water-wave structures manipulating particles" Nature 638, 394–400 (2025)

Y. Shen*, H. Wang, and S. Fan, "Free-space topological optical textures," Adv. Opt. Photonics 17(2) 295-374 (2025)

Optical Angular Momentum

Structured light and vector vortex beams carrying spin and orbital angular momentum (OAM). We specially focus on the tunable and multi-singularity structured light, controlled by metadevices, lasers and digital holograms, and the applications of their spin-to-orbital coupling.

Featured works:

Y. Shen, et al., “Optical vortices 30 years on: OAM manipulation from topological charge to multiple singularities,” Light: Sci. & Appl. 8:90 (2019) [ESI highly cited paper]

​​​Y. Shen*, et al., “Structured ray-wave vector vortex beam in multiple degrees of freedom from a laser,” Optica 7(7), 820–831 (2020) [On the cover]

​​​Y. Shen*, et al., “Deep-learning-based recognition of multi-singularity structured light.” Nanophotonics 11(4), 779–786 (2022) [Invited Article]

Skyrmions and Topological Quasiparticles

Skyrmions are a special type of topological particles with sophisticated spin textures in solid-state and quantum physics, but only recently being possible to be controlled in structured optical fields. The elegant vectorial structure and topological tunability of optical skyrmion meets the urgent requirements of higher-dimensional structured light.

Featured works:

Y. Shen*, et al.,  "Optical skyrmions and other topological quasiparticles of light" Nat. Photonics 18, 15–25 (2024)

Y. Shen*, "Topological bimeronic beams" Opt. Lett. 46, 3737-3740 (2021) [Editor's Pick]

Y. Shen*, et al., “Generation of optical skyrmions with tunable topological textures,” ACS Photonics 9, 296–303 (2022) [On the journal cover]

AI Photonics

We develope AI-driven frameworks to revolutionize the technologies of complex topological wave structures, their resilient detection under ultrasmall super-resolution events, environmental perturbations, efficient transmission, and inverse design for enhanced stability properties.

Featured works:

​​​Y. Shen*, et al., "Spatial nonlinear conversion of structured light for machine learning based ultra-accurate information networks" Laser Photonics Rev. 2301225 (2024) [On the cover]

Y. Wang, E. A. Chan, C. Rendón-Barraza, Y. Shen, E. Plum, J.-Y. Ou, "2D Super-Resolution Metrology Based on Superoscillatory Light," Adv. Sci. 11, 2404607 (2024)

High-dimensional Quantum Optics

Photons can be structured to blend quantum information and structured light in the context of high-dimensional and multidimensional entanglement. Exploration of multi-partite non-separable states in higher-dimensional entangled light enables novel quantum-classical-connected applications.

Featured works:

Y. Shen*, et al., “Creation and control of high-dimensional multi-partite classically entangled light,” Light: Sci. & Appl. 10, 50 (2021) [On the cover]

Y. Shen* and C. Rosales-Guzmán, "Nonseparable states of light: From quantum to classical," Laser Photonics Rev. 16, 2100533 (2022)

Anapole and Toroidal Electrodynamics

The unique properties of toroidal excitations in matter and free-space, including nonradiating anapole configuration, flying doutghnut, and space-time non-separable pulses, which provide a unique new tool to probe the physics of interactions and topological information transfer.

Featured works:

A. Zdagkas, Y. Shen, et al., “Observation of Toroidal Pulses of Light,” Nat. Photonics 16, 523–528 (2022) [On the cover]

Y. Shen*, et al., “Supertoroidal light pulses as electromagnetic skyrmions propagating in free space,” Nat. Commun. 12, 5891 (2021)

Y. Shen*, et al., "Topological Transformation and Free-Space Transport of Photonic Hopfions," Adv. Photonics 5(1), 015001 (2023) [On the cover]

Metamaterials, Metasurfaces and Nanophotonics

Metasurface-integrated micro- or nano-scale structured light generator holds transformative potential across interdisciplinary domains and practical applications, including materials science, information technology, biological science, quantum physics.

Featured works:

Y. Shen,* et al. "Optical skyrmions from metafibers with subwavelength features," Nat. Commun. 15, 10141 (2024)

Y. Meng, F. He, Y. Shen, et al., “Ultracompact Graphene-Assisted Tunable Waveguide Couplers with High Directivity and Mode Selectivity,” Sci. Rep. 8:13362 (2018)

Y. Shen,* et al.  “Free-form flexible metasurfaces robustly generating microwave skyrmions” Adv. Mater. 38(25), e18268 (2026)

Ultrafast, Nonlinear, Space-Time Optics

Researches includes mode-locking laser, chirped-pulse amplification (CPA), and ultrafast nonlinear fiber optics, spatiotemporal light fields, gain-phase modulation theory. We recently focused on few-cycle ultrafast structured light and its nonlinear effects.

Featured works:

Y. Shen, et al., “Gain-phase modulation in chirped-pulse amplification,” Phys. Rev. A 96, 043851 (2017)

Y. Shen*, et al., “Supertoroidal light pulses as electromagnetic skyrmions propagating in free space,” Nat. Commun. 12, 5891 (2021)

Laser Technologies

Structured light can be emitted directly from a laser, by imprinting an intracavity twist on the circulating light, but it requires judicious laser cavity design to break nature’s angular momentum degeneracy. Without this, the laser produces equal measures of both helicities, for no net angular momentum.