Zi-Lan Deng

• Doctor of Philosophy
• Professor at Jinan University

The emerging meta-holograms rely on arrays of intractable meta-atoms with various geometries and sizes for customized phase profiles that can precisely modulate the phase of a wavefront at an optimal incident angle for given wavelengths. The stringent and band-limited angle tolerance remains a fundamental obstacle for their practical application, i...

Phase, polarization, amplitude, and frequency represent the basic dimensions of light, playing crucial roles for both fundamental light–material interactions and all major optical applications. Metasurfaces have emerged as a compact platform to manipulate these knobs, but previous metasurfaces have limited flexibility to simultaneous control them....

Malus’ law regulating the intensity of light when passed through a polarizer, forms the solid basis for image steganography based on orthogonal polarizations of light to convey hidden information without adverse perceptions, which underpins important practices in information encryptions, anti-counterfeitings, and security labels. Unfortunately, the...

Optical skyrmions have recently been constructed by tailoring vectorial near-field distributions through the interference of multiple surface plasmon polaritons, offering promising features for advanced information processing, transport and storage. Here, we provide experimental demonstration of electromagnetic skyrmions based on magnetic localized...

Metasurface polarization optics, manipulating polarization using metasurfaces composed of subwavelength anisotropic nanostructure array, has enabled a lot of innovative integrated strategies for versatile and on-demand polarization generation, modulation, and detection. Compared with conventional bulky optical elements for polarization control, met...

Polaronic effects involving stabilization of localized charge character by structural deformations and polarizations have attracted considerable investigations in soft lattice lead halide perovskites. However, the concept of polaron assisted nonlinear photonics remains largely unexplored, which has a wide range of applications from optoelectronics...

Optically addressable spin-photon interfaces in monolayers of transition metal dichalcogenides (TMDCs) are pivotal to realizing classical and quantum operations using photons. Valley pseudospin in TMDCs allows circularly polarized light to be coupled with electron (hole) spin, thus enabling initialization and readout of both classical and quantum i...

Topological properties of energy flow of light are fundamentally interesting and may introduce novel physical phenomena associated with directional light scattering and optical trapping. In this Letter, skyrmionlike structures formed by Poynting vectors are unveiled in the focal region of two pairs of counterpropagating cylindrical vector vortex be...

Chirality describes mirror symmetry breaking in geometric structures or certain physical quantities. The interaction between chiral structure and chiral light provides a rich collection of means for studying the chirality of substances. Recently, optical chiral metasurfaces have emerged as planar or quasi-planar photonic devices composed of subwave...

As a fundamental property of light, polarization serves as an excellent information encoding carrier, playing significant roles in many optical applications, including liquid crystal displays, polarization imaging, optical computation and encryption. However, conventional polarization information encoding schemes based on Malus’ law usually conside...

Dynamic access to quasi-bound states in the continuum (q-BICs) offers a highly desired platform for silicon-based active nanophotonic applications, while the prevailing tuning approaches by free carrier injections via an all-optical stimulus are yet limited to THz and infrared ranges and are less effective in visible bands. In this work, we present...

Lanthanide-doped upconversion nanoparticles emerged recently as an attractive material platform underpinning a broad range of innovative applications such as optical cryptography, luminescent probes, and lasing. However, the intricate 4f-associated electronic transition in upconversion nanoparticles leads only to a weak photoluminescence intensity...

Topological properties of energy flow of light are fundamentally interesting and have rich practical applications in optical manipulations. Here, skyrmion-like structures formed by Poynting vectors are unveiled in the focal region of a pair of counter-propagating cylindrical vector vortex beams in free space. A N\'eel-Bloch-N\'eel skyrmion type tra...

Lanthanide-doped upconversion nanoparticles emerged recently as an attractive material platform underpinning a broad range of innovative applications such as optical cryptography, luminescent probes, and lasing. However, the intricate 4f-associated electronic transition in upconversion nanoparticles leads only to a weak photoluminescence intensity...

The combination of conventional polarization optical elements, such as linear polarizers and waveplates, is widely adopted to tailor light’s state of polarization (SOP). Meanwhile, less attention has been given to the manipulation of light’s degree of polarization (DOP). Here, we propose metasurface-based polarizers that can filter unpolarized inci...

Optical metasurfaces with high quality factors (Q-factors) of chiral resonances can boost substantially light-matter interaction for various applications of chiral response in ultrathin, active, and nonlinear metadevices. However, current approaches lack the flexibility to enhance and tune the chirality and Q-factor simultaneously. Here, we suggest...

Bessel beams, with their non-diffractive property, have attracted great interest in recent years. Optical needle shaping of Bessel beams is highly desired in many applications, however, this typically requires low numerical aperture (NA) bulky 4f confocal systems incorporated with spatial light modulators or round filters. Here, we employ a circula...

Coupled resonances in non‐Hermitian systems can lead to exotic optical features, such as bound states in the continuum (BICs) and exceptional points (EPs), which have been recently emerged as powerful tools to control the propagation and scattering of light. Yet, similar tools to control diffraction and engineer spatial wavefronts have remained elu...

Optical holography capable of the complete recording and reconstruction of light’s wavefront, plays significant roles on interferometry, microscopy, imaging, data storage, and three-dimensional displaying. Conventional holography treats light as scalar field with only phase and intensity dimensions, leaving the polarization information entirely neg...

We employ the physics of chiral bound state in the continuum and suggest planar chiral metasurfaces with near-perfect circular dichroism (CD). We demonstrate experimentally metasurfaces with CD=0.9 with Q factor exceeding Q=390 at optical frequencies.

Optical metasurfaces with high-Q chiral resonances can boost light-matter interaction for various applications of chiral response for ultrathin, active, and nonlinear metadevices. Usually, such metasurfaces require sophisticated depth-resolved nanofabrication to realize subwavelength stereo-nanostructures, posing overwhelming challenges, especially...

Resonance coupling in non-Hermitian systems can lead to exotic features, such as bound states in the continuum (BICs) and exceptional points (EPs), which have been widely employed to control the propagation and scattering of light. Yet, similar tools to control diffraction and engineering spatial wavefronts have remained elusive. Here, we show that...

Smith-Purcell radiation (SPR) is a kind of electromagnetic wave radiation that happens when an energetic beam of electrons passes very closely parallel to the surface of a ruled optical diffraction grating. The frequency of radiation waves varies in the upper and lower space of the grating for different electron velocity, satisfying the SPR relatio...

A proposal of Fano lasing spaser is demonstrated in a superlattice meta-grating, in which the spatial-temporal lasing dynamics is investigated by a semiclassical model that involves the coupling between full-wave electromagnetic equations and electronic rate equations. The out-of-phase dark mode and in-phase bright mode supported by the meta-gratin...

Optical skyrmions have recently been constructed by tailoring electric field distributions through the interference of multiple surface plasmon polaritons, offering promising features for advanced information processing, transport and storage. Here, we construct topologically robust plasmonic skyrmions in a wisely tailored space-coiling meta-struct...

The control of polarization, an essential property of light, is of broad scientific and technological interest. Polarizers are indispensable optical elements for direct polarization generation. However, arbitrary polarization generation, except that of common linear and circular polarization, relies heavily on bulky optical components such as casca...

Metagratings have been shown to form an agile and efficient platform for extreme wavefront manipulation, going beyond the limitations of gradient metasurfaces. Here, we theoretically show perfect unitary diffraction in all-dielectric transmissive metagratings using simple rectangular inclusions with neither high index nor high respect ratio require...

Owing to its good air-stability and high refractive index, two-dimensional (2D) noble-metal dichalcogenide shows intriguing potentials for versatile flat optics applications. However, light field manipulation at the atomic scale is conventionally considered unattainable since the small thickness and intrinsic losses of 2D materials completely suppr...

Manipulating the light emission direction and boosting its directivity have essential importance in integrated nanophotonic devices. Here, we theoretically propose a single dielectric silicon nanoblock as an efficient, multifunctional and ultracompact all-dielectric nanoantenna to direct light into a preferential direction. Unidirectional scatterin...

The control of polarization, an essential property of light, is of wide scientific and technological interest. Polarizer is an indispensable optical element for direct polarization generations. Except common linear and circular polarizations, however, arbitrary polarization generation heavily resorts to bulky optical components by cascading linear...

In article number 1910610, Zi‐Lan Deng, Guixin Li, Xiangping Li, and co‐workers show how multi‐dimensional wavefront shaping of light in amplitude, polarization, phase, and frequency can be realized simultaneously through a single layer multi‐freedom metasurface. Consequently, full‐color complex‐amplitude vectorial holographic image can be vividly...

The merging of metasurface and holography brings about unprecedented opportunities for versatile manipulation of light in terms of both far-field wavefront and near-field profile. In this book, a brief evolving history from surface plasmon polariton holography to metamaterial holography and finally to metasurface holography is introduced at first....

Metagratings have been shown to form an agile and efficient platform for extreme wavefront manipulation, going beyond the limitations of gradient metasurfaces. Previous approaches for transmissive metagratings have resorted on compound asymmetric inclusions to achieve single-channel near-perfect diffraction. However, such complex inclusions are sen...

Phase, polarization, amplitude and frequency represent the basic dimensions of light, playing crucial roles for both fundamental light-mater interactions and all major optical applications. Metasurface emerges as a compact platform to manipulate these knobs, but previous metasurfaces have limited flexibility to simultaneous control them. Here, we i...

Along with the polarization states of light, wavelength is another basic attribute of light. Manipulation of wavelength together with the metasurface is promising for many applications, such as optical dispersion-controlling devices [1–12], selective color routing [13, 14], and 3D full-color holographic displays [15–20].

At the time when holography was invented, the “holo” information of a light wavefront represent both the intensity and phase information. Actually, the polarization states of light are also basic attribute of light. In earlier times, holograms are recorded in refractive bulky materials that are typically polarization insensitive, so polarization st...

The versatile and powerful functionalities supported by metasurfaces are fundamentally governed by the underlying phase modulation rules based on the resonance and scattering properties of the individual meta-atoms. Typically, by varying the shape, orientation, size, and position of the meta-atoms, one can apply the resonant phase, geometric P-B ph...

Traditional holography only deals with the wavefront shaping of free-space waves through interference of multiple coherent light beams. Holographic interference technique has been successfully applied in surface plasmon waves [1], and the wavefronts of both free-space wave and surface wave could be shaped by a general holographic way in a metagrati...

Holography was an old technology but was persistently studied for more than 70 years in the optics community due to its powerful ability to arbitrarily shape free-space wavefront by controlling “holo” attributes typically including both amplitude and phase of the light field. Although many fascinating applications such as holographic data storage,...

The holography technology was invented by Dennis Gabor in 1948 when he tried to correct the spherical aberrations of the electron microscopy by introducing a so-called “electron interference microscope” [1]. The proposed principle provided a complete record of amplitudes and phases in one diagram, and since then was widely studied to reconstruct bo...

Manipulation of light fields at will is a long-sought goal in the optics community. In this regard, holography, a technology that can modulate an arbitrary light wavefront including not only its intensity but also the phase information in a spatial domain, was invented 60 years ago [1]. Traditional holography has been extensively studied by the inf...

Two-dimensional (2D) noble-metal dichalcogenides have emerged as a new platform for the realization of versatile flat optics with a considerable degree of miniaturization. However, light field manipulation at the atomic scale is widely considered unattainable since the vanishing thickness and intrinsic losses of 2D materials completely suppress bot...

Transcending the common perceptions of phase‐gradient metasurfaces, metagratings emerge as a new paradigm for wavefront manipulation directly on the desired diffraction order with ultrahigh deflection angles. However, previous metagratings rely on directional scattering caused by multiresonant interference between multiple separate inclusions, of w...

Conventional optical elements to realize spin-to-orbital angular momentum conversion of light can only allow conversion of opposite spin angular momentum (SAM) states into opposite orbital angular momentum (OAM) states. This limitation was recently broken by a metasurface based J-plate with combined geometric and propagation phase design that can c...

Light manipulation at the nanoscale is the vanguard of plasmonics. Controlling light radiation into a desired direction in parallel with high optical signal enhancement is still a challenge for designing ultracompact nanoantennas far below subwavelength dimensions. Here, we theoretically demonstrate the unidirectional emissions from a local nanoemi...

We theoretically propose a sensitive label-free sensor with high figure of merit (FoM) based on Fano resonances on a plasmonic metasurface whose unit cell consists of double two-split nanorings by finite-element method. The unit cell of the proposed Fano resonant structure comprises of two thin gold nanorings each with two splits. Two Fano modes ar...

High-speed optical amplitude modulation is important for optical communication systems and sensors. Moreover, nano-optical modulators are important for developing optical-communication-aided high-speed parallel-operation processors and micro-biomedical sensors for inside-blood-capillary examinations or microsurgery operations. In this paper, we hav...

In this paper, we demonstrated a Fano resonant superlattice metasurface structure composed of bilayer trimeric metallic stripes in each unit cell. It can simultaneously support two types of Fano resonances, which individually possesses electric and magnetic properties at microwave frequencies, respectively. The electric Fano resonance is generated...

The nano groove can highly improve the transmittance of coaxial nanoring aperture due to the excitation of surface plasmon polariton (SPP). The total angular momentum carried by incident beam is reserved in the whole process and transferred to the SPP, thus the vortex SPP carrying orbital angular momentum is generated. The enhanced transmittance of...

A highly efficient and broad light absorber capable of wide-angle absorption in the visible and near infrared range is presented and numerically investigated for energy harvesting in a simple geometry. According to the calculated results, the proposed device has a peak absorption level of about 99.95%. The actual absorption efficiency is 76.35%, wh...

High-performance meta-holograms are experimentally demonstrated in a near-unity-efficiency metagrating platform without any size or shape variation of the meta-atoms, which is robust against large incident angles, and sustains high diffraction efficiency in a broadband.

we propose a novel metasurface designs by exploiting displacements instead of the size and shape between adjacent meta-atoms, leading to dispersionless and full phase and polarization control of arbitrary wavefronts.

In this paper, we report on the theoretical and numerical study of the transmission of circularly polarized vortex beams through a plasmonic coaxial nanoring. We show that the transmission peak wavelength of an incident circularly polarized vortex beam is dominantly governed by the total angular momentum, which determines the coupling to the plasmo...

Photonic metasurface, a 2D array of plasmonic or dielectric optical meta-atoms, provides a versatile and compact platform for manipulating the polarization, phase and amplitude of light. It has been used to design planar optical functional elements such as ultrathin metasurface lens, metasurface waveplates, polarization beam splitter and so on. Mor...

We report spectral splitting behaviors based on Fano resonances in a novel simple planar metasurface composed of gold nanobars and nanorings. Multiple plasmonic modes and sharp Fano effects are achieved in a broadband transmittance spectrum by exploiting the rotational symmetry of the metasurface. The transmission properties are effectively modifie...

We present a metasurface composed of graphene ribbon superlattice that supports plasmonic Fano resonance in a simple symmetric configuration. Without the necessity of changing the geometry size of graphene ribbons, we tune the Fano resonance of the metasurface containing identical graphene ribbons by simply changing the global or local periods of t...

We show that, a metasurface composed of subwavelength metallic slit array embedded in an asymmetric environment can exhibit either extraordinary optical transmission (EOT) or extraordinary optical diffraction (EOD). By employing an analytical model expansion method and the diffraction order chart in k-vector space, we found that the resonance decay...

We show that, a metasurface composed of subwavelength metallic slit array embedded in an asymmetric environment can exhibit either extraordinary optical transmission (EOT) or extraordinary optical diffraction (EOD). By employing an analytical model expansion method and the diffraction order chart in k-vector space, we found that the resonance decay...

We propose a new scheme of lasing in a nano-grating with Fano resonance by the independent control of dark and bright modes. The controllability of both dark and bright modes can be achieved by fine-tuning the widths of two kinds of metallic stripes in the nano-grating. It enables the match between resonant frequencies of the nano-grating structure...

We present an approach to build multiwavelength achromatic metasurface that can work in off-axis configuration with an ultra-wide applicable incident angle range for visible light. The metasurface is constructed by combining multiple metallic nano-groove gratings, which support enhanced diffractions for transverse magnetic polarization in an ultraw...

Recently, an achromatic metasurface was successfully demonstrated to deflect light of multiple wavelengths in the same direction and it was further applied to the design of planar lenses without chromatic aberrations [Science, 347, 1342(2015)]. However, such metasurface can only work for normal incidence and exhibit low conversion efficiency. Here,...

In this paper, we present a simple trimeric metasurface consisting of three dipolar resonators in each unit cell, to achieve the independent controlling over both the broad bright mode and the sharp dark mode of Fano resonances. Through both the finite difference time domain simulation and microwave experiment, we find that spectral positions of th...

We analytically show that an incident light can be almost completely diffracted into the -1(st) order in wide-angle and broadband by suitably designed thin metallic nano-gratings with simple rectangular cross sections. Such extraordinary optical diffraction results from the excitation of localized cavity modes and exists even when the grating perio...

A reflection metasurface, composed of metallic annular rings, is presented for realizing high-efficient and polarization-independent focusing. By varying the inner and outer radii of the isotropic rings, we can achieve a full modulation on the phase from -180°to 180°. By properly arranging the annular rings, we design gradient metasurfaces for focu...

Controlling of the lineshape of Fano resonance attracts much attention recently due to its wide capabilities for lasing, biosensing, slow-light applications and so on. However, the controllable Fano resonance always requires stringent alignment of complex symmetry-breaking structures and thus the manipulation could only be performed with limited de...

We propose a scheme that the material dispersion can be immune in a kind of photonic topological metacrystal with uniform permittivity and permeability but staggered bianisotropy. The topological behaviors can be maintained even though the metamaterials are intrinsically dispersive. A nontrivial topological band gap with a large gap spin Chern numb...

We proposed a group-theory method to calculate topological invariant in bi-isotropic photonic crystals invariant under crystallographic point group symmetries. Spin Chern number has been evaluated by the eigenvalues of rotation operators at high symmetry k-points after the pseudo-spin polarized fields are retrieved. Topological characters of photon...

We propose a plasmon-induced transparency (PIT) nanocavity for achieving nanoscopic coherent light source. The compact cavity is constructed by a pair of detuned nano-stubs incorporated with four-level gain medium. The PIT response enables the reduction of the coupling loss from cavity to waveguide while keeping the cavity size unchanged, different...

Using the dyadic Green function (GF) with a multilayer medium, we propose an eigendecomposition (ED) analysis of a plasmonic system composed of a one-dimensional periodic metal nanoparticle chain and planar layered structure. An effective eigenpolarizability involving the collective effects of both the chain and the layered structure is well define...

Plasmonic waveguide with detuned resonators is studied in plasmon-induced transparency window. Gain coefficient is quadratic with detuning in lasing oscillation condition. Spectra in amplification regime below lasing threshold have large group delay, high transmittance and narrow linewidth. A straight-forward biosensing application is demonstrated.

A gain-assisted plasmonic waveguide with two detuned resonators is investigated in the plasmon-induced transparency window. Phase map is employed to study power transmittance and group delay for varying gain coefficients and frequency detunings of the two resonators. The gain coefficient for lasing oscillation condition is analytically shown to var...

A gain-assisted plasmonic waveguide with two detuned resonators is investigated in the plasmon-induced transparency window. Phase map is employed to study power transmittance and group delay for varying gain coefficients and frequency detunings of the two resonators. The gain coefficient for lasing oscillation condition is analytically shown to var...

We investigated the plasmonic modes in a two-dimensional quasicrystalline array of metal nanoparticles. The polarization of the modes is in the array plane. A simplified eigen-decomposition method is presented with the help of rotational symmetry. Two kinds of anti-phase ring modes with radial and tangential polarizations are of highest spatial loc...