About

Shanhui Fan is the Joseph and Hon Mai Goodman Professor in the School of Engineering at Stanford University. He holds the positions of Professor of Electrical Engineering, Professor of Applied Physics (by courtesy), and Senior Fellow in the Precourt Institute for Energy. Additionally, he is a faculty member of the Edward L. Ginzton Laboratory, where he served as Director from 2014 to 2021. His research focuses on fundamental studies of nanophotonic structures, particularly photonic crystals and meta-materials, and their applications in energy and information technology. Professor Fan has published over 700 refereed journal articles, delivered more than 400 plenary, keynote, and invited talks, and holds over 80 granted U.S. patents. His research achievements have been recognized with several awards, including the R. W. Wood Prize, the Simons Investigator in Physics, and the Vannevar Bush Faculty Fellowship. He is an elected member of the National Academy of Sciences, the National Academy of Engineering, and the American Academy of Arts and Sciences, and is a Fellow of IEEE, APS, Optica, SPIE, and NAI. Professor Fan completed his undergraduate studies in physics at the University of Science and Technology of China from 1988 to 1992 and earned his Ph.D. in theoretical condensed matter physics from the Massachusetts Institute of Technology in 1997.

Research topics

• Computer Science
• Physics
• Optics
• Engineering
• Materials science
• Optoelectronics
• Electrical engineering
• Composite material
• Meteorology
• Electronic engineering
• Computer Security
• Artificial Intelligence
• Nanotechnology
• Telecommunications
• Environmental science
• Mechanical engineering
• Algorithm
• Computational physics
• Engineering physics
• Condensed matter physics
• Mathematical analysis
• Quantum mechanics
• Nuclear engineering
• Architectural engineering

Selected publications

• Realization of the tellegen effect in resonant optical metasurfaces

  eLight · 2026-03-02

  articleOpen access

  Abstract The nonreciprocal magnetoelectric effect in Tellegen materials enables exotic phenomena such as axion-modified electrodynamics and fosters the development of magnet-free nonreciprocal media. As the nonreciprocal counterpart to the well-known chiral electromagnetic response, it offers a parallel framework in which many concepts developed for chiral materials can be translated to Tellegen media, potentially unlocking new avenues for fundamental studies and applications. Although predicted over 75 years ago and observed in only a handful of natural materials with very low strength, the strong optical Tellegen effect has remained experimentally elusive. Here, we report the first experimental demonstration of a resonant optical diagonal Tellegen effect in a metasurface, showcasing a response that is 100 times greater than that of any known natural material. This optical metasurface, consisting of randomly distributed cobalt-silicon nanoscatterers with strong shape anisotropy, utilizes spontaneous magnetization to achieve a robust Tellegen effect without the need for an external magnetic field. In addition to the Tellegen response, the metasurface exhibits both gyroelectric and gyromagnetic effects, contributing to nonreciprocal cross-polarized light reflection. We introduce a technique to independently extract the amplitudes of these three effects using conventional magneto-optical single-side-illumination measurements. The observation of the resonant Tellegen effects in the optical frequency range may lead to the experimental observation of axionic electrodynamics and compact bias-free nonreciprocal optical devices.

  PublisherOA PDFDOI

• Experimental observation of energy-band Riemann surface

  Science Advances · 2026-03-18

  articleOpen accessSenior authorCorresponding

  Non-Hermiticity naturally arises in physical systems that exchange energy with their environment. The presence of non-Hermiticity leads to many topological physics phenomena and device applications. In the non-Hermitian energy band theory, the foundation of these physics and applications, both energies and wave vectors take complex values. The energy bands thus become a Riemann surface, and such an energy-band Riemann surface underlies all important signatures of non-Hermitian topology. Despite a long history and recent theoretical interests, the energy-band Riemann surface has not been experimentally studied. Here, we provide a photonic observation of the energy-band Riemann surface of a non-Hermitian system. This is achieved by a tunable imaginary gauge transformation in photonic synthetic frequency dimensions. From measured topologies of the Riemann surface, we reveal the complex-energy winding, the open-boundary-condition spectrum, the generalized Brillouin zone, and the branch points. Our findings demonstrate a unified framework in the studies of diverse effects in non-Hermitian topological physics through an experimental observation of energy-band Riemann surfaces.

  PublisherDOI

• John Joannopoulos (1947–2025)

  Nature Photonics · 2025-11-01

  article
  PublisherDOI

• Twist-Induced Beam Steering and Blazing Effects in Photonic Crystal Devices

  Light Science & Applications · 2025-08-07 · 3 citations

  articleOpen access

  Twisted bilayer photonic crystals introduce a twist between two stacked photonic crystal slabs, enabling strong modulation of their electromagnetic properties. The change in the twist angle strongly influences the resonant frequencies and available propagating diffraction orders with applications including sensing, lasing, slow light or wavefront engineering. In this work, we design and analyze twisted bilayer crystals capable of steering light in a direction controlled by the twist angle. To achieve beam steering, the device efficiently routes input power into a single, twist-dependent, transmitted diffraction order. The outgoing light then follows the orientation of this diffraction order, externally controlled by the twist angle. Our study shows, using systematic exploration of the design space, how the device resembles blazed gratings by effectively canceling the undesired diffraction orders. The optimized devices exhibit a shared slant dependent on the selected diffraction order and that proves robust to the twist angle. Our analysis is supported by a classical blazing model and a data-oriented statistical analysis. The data-oriented approach is steered by high-efficiency heuristic optimization method, which enabled the design of optimized devices demonstrating an efficiency above 90% across twist angles ranging from 0 to 30° for both TE and TM polarizations. Extending the optimization to include left- and right-handed polarizations yields overall accuracy nearing 90% when averaged across the entire 0 to 60° control range. Finally, with the identification of the blazing effect in this initially black box structure, we show one can consider simpler design for a first prototype.

  PublisherOA PDFDOI

• Lorentz–Drude Dipoles in the Radiative Limit and Their Modeling in Finite‐Difference Time‐Domain Methods

  Annalen der Physik · 2025-06-25

  articleOpen accessSenior authorCorresponding

  Abstract The Lorentz–Drude model for electric dipoles is a classical framework widely used in the study of dipole dynamics and light‐matter interactions. This article focuses on the behavior of Lorentz–Drude dipoles when their radiative rate dominates their energy loss. It is asserted that dipole radiation losses do not count toward phenomenological dipole losses if the driving field is interpreted as the total field at the dipole. In particular, if the dipole does not contain non‐radiative losses, then the Lorentz–Drude damping term should be removed. This is verified by self‐consistent implementations of point dipoles in finite‐difference time‐domain simulations, which also provide a method to directly compute the transport properties of light when dipoles are present.

  PublisherOA PDFDOI

• Dynamic realization of emergent high-dimensional optical vortices

  Nature Communications · 2025-11-05 · 1 citations

  articleOpen access

  The dimensionality of vortical structures has recently been extended beyond two dimensions, providing additional topological complexity and robustness for high-capacity information processing and turbulence control. The generation of high-dimensional vortical structures has mostly been demonstrated in classical systems through the complex interference of fluidic, acoustic, or electromagnetic waves. However, natural materials rarely support three- or higher-dimensional vortical structures and their physical interactions. Here, we experimentally demonstrate a high-dimensional gradient thickness optical cavity (GTOC) in which the optical coupling of planar metal-dielectric multilayers implements topological interactions across multiple dimensions. At non-trivial topological phases, high-dimensional GTOC induces high-dimensional vortical structures in generalized parameter space in three, four dimensions, and beyond. These emergent high-dimensional vortical structures are observed under electro-optic tomography as optical vortex dynamics in two-dimensional real-space, employing the optical thicknesses of dielectric layers as synthetic dimensions. Our findings hold significant promise for emulating high-dimensional physics and developing active topological photonic devices. Higher dimensional vortical structures are being explored in optical and acoustic systems via complex wave interference. However, deterministic generation has not been reported. Here, the authors demonstrate emergent 3D optical vortices in a gradient-thickness optical cavity.

  PublisherOA PDFDOI

• Ultrafast space-time optical merons in momentum-energy space

  Nature Communications · 2025-09-29 · 5 citations

  articleOpen access

  Skyrmions, topologically non-trivial localized spin structures, are fertile ground for exploring emergent phenomena in condensed matter physics and next-generation magnetic-memory technologies. Although magnetics and optics readily lend themselves to two-dimensional realizations of spin texture, only recently have breakthroughs brought forth three-dimensional (3D) magnetic skyrmions, whereas their optical counterparts have eluded observation to date because their realization requires precise control over the spatiotemporal spectrum. Here, we demonstrate freely propagating 3D-localized optical skyrmionic structures with a non-trivial topological profile by imprinting meron polarization texture on open and closed spectral surfaces in the momentum-energy space of an ultrafast optical wave packet. Precise control over the spatiotemporal polarization texture of light – a key requisite for synthesizing 3D optical merons – is the product of synergy between novel methodologies in the modulation of light jointly in space and time, digital holography, and large-area birefringent metasurfaces. Our work advances the fields of polarization optics and topological photonics and may inspire new developments in imaging, metrology, optical communications, and quantum technologies. Recently, the increased capabilities in generating pulsed optical fields that are rigidly transported in linear media without diffraction or dispersion has opened the path to realisation of 3D optical skyrmionic structures. Here, the authors demonstrate 3D-localized optical merons by imprinting polarization textures onto the momentum-energy space of ultrafast light pulses.

  PublisherOA PDFDOI

• Experimental Realization of the Optical Tellegen Effect in Nonreciprocal Metasurfaces

  2025-09-01

  article

  Nonreciprocal magnetoelectric coupling, known as the Tellegen effect, promises pioneering potential for applications such as magnet-free isolators and axion-like electrodynamics, yet its realization in optical regimes remains elusive. Here, we present the first experimental demonstration of an optical Tellegen metasurface. Composed of cobalt-silicon nanocones with pronounced shape anisotropy, this metasurface leverages spontaneous magnetization to induce a robust Tellegen response, alongside gyroelectric and gyromagnetic effects, enabling nonreciprocal light reflection. Furthermore, we introduce a novel method to independently quantify the amplitudes of these effects using a standard magneto-optical measurement. Our results show a resonant Tellegen response that is 100 times stronger than that of any known natural material.

  PublisherDOI

• Variational processing of multimode squeezed light

  ArXiv.org · 2025-09-20

  preprintOpen accessSenior author

  Integrated multimode quantum optics is a promising platform for scalable continuous-variable quantum technologies leveraging multimode squeezing in both the spatial and spectral domains. However, on-chip measurement, routing and processing the relevant ``supermodes'' over which the squeezing resource is distributed still scales quadratically with the number of modes $N$, causing rapid increase in photonic circuit size and number of required measurements. Here, we introduce a variational scheme, relying on self-configuring photonic networks (SCN) that learns and extracts the most-squeezed supermodes sequentially, reducing both the circuit size and the experimental overhead. Using homodyne measurement as a cost function, a sparse SCN discovers the $l\ll N$ most significant supermodes using $O(lN)$ physical elements and optimization steps. We analyze and numerically simulate these architectures for both real-space and frequency-domain implementations, showing a fidelity close to unity between the learned circuit and the supermode decomposition, even in the presence of optical losses and detection noise. In the frequency domain, we show that circuit size can be further reduced by using inverse-designed surrogate networks, which emulate the layers learned thus far. Using two different frequency encoding schemes -- uniformly- and non-uniformly-spaced frequency bins -- we reduce an entire network (learning all $N$ supermodes) to $O(N)$ and even $O(1)$ modulated cavities. Our results point toward chip-scale, resource-efficient quantum processing units and demultiplexers for continuous variable processing in multimode quantum optics, with applications ranging from quantum communication, metrology, and computation.

  PublisherOA PDFDOI

• Near-Field Dynamical Casimir Effect

  Physical Review Letters · 2025-09-10 · 1 citations

  articleSenior author

  We propose the dynamical Casimir effect in a time-modulated near-field system at finite temperatures. The system consists of two bodies made of polaritonic materials that are brought in close proximity to each other, and the modulation frequency is approximately twice the relevant resonance frequencies of the system. We develop a rigorous fluctuational electrodynamics formalism to explore the produced Casimir flux, associated with the degenerate as well as the nondegenerate two-polariton emission processes. We have identified flux contributions from both quantum and thermal fluctuations at finite temperatures, with a dominant quantum contribution even at room temperature under the presence of a strong near-field effect. We have found that the Casimir flux can be generated with a smaller modulation frequency through the higher-order dynamical Casimir effect. We have conducted a nonclassicality test for the total radiative flux at finite temperatures, and we have shown that nonclassical states of emitted photons can be obtained for a high temperature up to ∼250 K. Our findings open an avenue for the exploration of the dynamical Casimir effect beyond cryogenic temperatures, and may be useful for creating tunable nanoscale nonclassical thermal states.

  PublisherDOI

Recent grants

• Collaborative Research: Designing Thermophotonic Materials for Passive Radiative Cooling

  NSF · $100k · 2017–2019

• Collaborative Research: CMOS Compatible On-Chip Optical Isolator

  NSF · $180k · 2012–2015

• Theory of Non-Reciprocal Photonic Crystals

  NSF · $270k · 2006–2009

• CAREER: Computational Studies of New Metallodielectric Structures for Manipulating Light At Sub-wavelengthscales

  NSF · $375k · 2002–2007

• FRG: Collaborative Research: Modeling, Computation, and Analysis of Optical Responses of Nano Structures

  NSF · $360k · 2010–2013

Frequent coauthors

• Zongfu Yu

  University of Wisconsin–Madison

  142 shared

• Cheng Guo

  Stanford University

  92 shared

• Peter B. Catrysse

  Stanford University

  86 shared

• Momchil Minkov

  Flex (United States)

  82 shared

• John D. Joannopoulos

  Institute for Soldier Nanotechnologies

  80 shared

• Avik Dutt

  University of Maryland, College Park

  66 shared

• Georgios Veronis

  Louisiana State University

  62 shared

• Luqi Yuan

  61 shared

Labs

• Fan Group at Stanford UniversityPI

  Not provided

Education

• Ph.D., Applied Physics

  Stanford University

  2003

• M.S., Applied Physics

  Stanford University

  1999

• B.S., Physics

  Tsinghua University

  1996