On-chip integrated metasystem for spin-dependent multi-channel color holography.

On-chip integrated metasurface driven by in-plane guided waves is of great interests in various light-field manipulation applications such as colorful augmented reality and holographic display. However, it remains a challenge to design colorful multichannel holography by a single on-chip metasurface. Here we present metasurfaces integrated on top of a guided-wave photonic slab that achieves multi-channel colorful holographic light display.

Inverse design of a light nanorouter for a spatially multiplexed optical filter.

It is attractive to use an optical nanorouter by artificial nanostructures to substitute the traditional Bayer filter for an image array sensor, which, however, poses great challenges in balancing the design strategy and the ease of fabrication. Here, we implement and compare two inverse design schemes for rapid optimization of RGGB Bayer-type optical nanorouter. One is based on the multiple Mie scattering theory and the adjoint gradient that is applicable to arrays of nanospheres with varying sizes, and the other is based on the rigorous coupled wave analysis and the genetic algorithm.

Möbius edge band and Weyl-like semimetal flat-band in topological photonic waveguide array by synthetic gauge flux.

The presence of gauge flux enabled by positive and negative hopping amplitude can lead to Möbius bands, which was recently demonstrated in both realistic acoustic and photonic lattices, twisted at = . Here, we show that the artificial gauge flux configuration can be achieved by exploiting the interactions between photonic and orbital-like fundamental modes in circular and peanut-shaped waveguides, respectively. By manipulating the interplay between the gauge fields and the crystal symmetry, we show that breaking the primitive translation symmetry through lattice site dimerization and deformation can cause the original Dirac semimetal phase, characterized by a four-fold Dirac point at the Brillouin zone center, to transform into various topological phases.

In situ preparation of Mn-doped perovskite nanocrystalline films and application to white light emitting devices.

Mn-doped perovskite nanocrystals have promised new optoelectronic applications due to their unique material properties. In the present study, Mn-doped perovskite nanocrystalline films were prepared in situ in a polymer matrix. The Mn-doped perovskite nanocrystals (PNCs) had good crystallinity and uniform size/spatial distributions in the polymer film.

Square-root topological state of coupled plasmonic nanoparticles in a decorated Su-Schrieffer-Heeger lattice.

The square-root operation can generate systems with new (to the best of our knowledge) topological phases whose topological properties are inherited from the parent Hamiltonian. In this Letter, we introduce the concept of square-root topology in the two-dimensional (2D) Su-Schrieffer-Heeger (SSH) model and construct a square-root topological square nanoparticle lattice (SRTL) by inserting additional sites into the original 2D SSH model. We find that the topological states in the SRTL are intriguingly different from those in the corresponding SSH model (with on-site potential) due to the change in symmetrical characteristics.

Nearly dispersionless multicolor metasurface beam deflector for near eye display designed by a physics-driven deep neural network.

Dispersion is one of the most important issues in see-through near eye displays with waveguide technology. In particular, the nanophotonics design is challenging but demanding. In this paper, we propose a design method for a multilayer achromatic metasurface structure for near eye display application by a physics-driven generative neural network.

Multiple Dirac points by high-order photonic bands in plasmonic-dielectric superlattices.

The emergence of Dirac points (DPs) characterizes the topological phase transition and the gapless interface states in composite metal-dielectric metamaterials. In this work, we study a kind of compound plasmonic-dielectric periodic structure (PDPS) which sustains both plasmonic modes and multiple photonic modes. The structure has primitive cell consisting of four layers made from triple constituent components.

Exploring optical resonances of nanoparticles excited by optical Skyrmion lattices.

Recently, optical Skyrmion lattices (OSLs) have been realized in evanescent electromagnetic fields. OSLs possess topologically stable field configurations, which promise many optics and photonics applications. Here, we demonstrate that OSLs can serve as versatile structured optical near-fields to assist with studies of a variety of photonic modes in nanoparticles.

Unidirectional excitation of plasmonic waves via a multilayered metal-dielectric-metal Huygens' nanoantenna.

Huygens' nanoantennas maintain orthogonal electric and magnetic dipole resonances satisfying the Kerker condition and can generate directional radiation in both the near-field and far-field regimes. Here we study a multilayered metal-dielectric-metal (MDM) Huygens' type nanoantenna which is capable of launching surface plasmon polaritons (SPPs) unidirectionally when excited by a dipole source. We show that the radiative decay rates of the dipole source are strongly enhanced by the antenna, and the generated SPP waves propagate in opposite directions at two different wavelengths.

Dual-band unidirectional forward scattering with all-dielectric hollow nanodisk in the visible.

High-index dielectric nanoantennas have become an emerging branch of optical nanoantennas, essentially due to their low loss. These types of nanoantennas can achieve both forward and backward unidirectional scattering, enabled by electric dipole and magnetic dipole interaction. Here, we show that the scattering directionality can be further enhanced if higher-order moments are properly balanced and reach the generalized Kerker condition at two different wavelengths in an all-dielectric hollow nanodisk.

Complex band structure of one-dimensional polariton crystal.

The exceptional point (EP), at which the relevant eigenvalues and eigenstates are simultaneously identical, typically exists in non-Hermitian systems with parity-time (PT) symmetric complex potentials, and gives rise to many intriguing behaviors in various physical realms. In this work, we explore the complex band structure of one-dimensional "polariton crystals" that can be constructed in waveguide-resonator coupled systems, with PT-symmetric potential. Analysis based on the transfer matrix and the coupled mode theory shows that the complex band structure is intimately determined by the interaction between the Bragg resonance and the polariton one, the gain/loss coefficients, in addition to the coupling strength.

Flavonoids isolated from Sinopodophylli Fructus and their bioactivities against human breast cancer cells.

Four prenylated flavonoids compounds 1-4, named sinopodophyllines A-D, and a flavonoid glycoside (compound 13), sinopodophylliside A, together with 19 known compounds (compounds 5-12 and 14-24) were isolated from the fruits of Sinopodophyllum hexandrum. The structures of new compounds were elucidated by extensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compounds 1-6, 9-11, and 14-17 were tested for their cytotoxicity against human breast-cancer T47D, MCF-7 and MDA-MB-231 cells in vitro, and compounds 2, 5, 6, 10 and 11 showed significant cytotoxicity (IC values < 10 μmol·L) against T47D cells.

Dual-Band Unidirectional Emission in a Multilayered Metal-Dielectric Nanoantenna.

Controlling the emission efficiency, direction, and polarization of optical sources with nanoantennas is of crucial importance in many nanophotonic applications. In this article, we design a subwavelength multilayer metal-dielectric nanoantenna consisting of three identical gold strips that are separated by two dielectric spacers. It is shown that a local dipole source can efficiently excite several hybridized plasmonic modes in the nanoantenna, including one electric dipole (ED) and two magnetic dipole (MD) resonances.

Sub-wavelength Unidirectional Antenna Realized by Stacked Spoof Localized Surface Plasmon Resonators.

The use of resonant structures to control scattering strength and directionality is of importance in various electromagnetic systems. Here we propose and demonstrate sub-wavelength unidirectional scattering by two nearby spoof localized surface plasmon resonators for microwave. The principle is that metal surfaces corrugated by grooves can support magnetic dipolar modes, as well as electric dipolar modes.

Absence of Exceptional Points in Square Waveguide Arrays with Apparently Balanced Gain and Loss.

The concept of parity-time (PT) symmetry in the field of optics has been intensively explored. This study shows the absence of exceptional points in a three-dimensional system composed of a square waveguide array with diagonally-balanced gain/loss distribution. More specifically, we show that an array of four coupled waveguides supports eight fundamental propagation supermodes, four of which are singlet, and the other two pairs are double degenerated.

Coexistence of Scattering Enhancement and Suppression by Plasmonic Cavity Modes in Loaded Dimer Gap-Antennas.

Plasmonic nanoantenna is of promising applications in optical sensing and detection, enhancement of optical nonlinear effect, surface optical spectroscopy, photoemission, etc. Here we show that in a carefully-designed dimer gap-antenna made by two metallic nanorods, the longitudinal plasmon antenna mode (AM) of bonding dipoles can compete with the transverse plasmonic cavity modes (CMs), yielding dramatically enhanced or suppressed scattering efficiency, depending on the CMs symmetry characteristics. More specifically, it is demonstrated that an appropriately loaded gap layer enables substantial excitation of toroidal moment and its strong interaction with the AM dipole moment, resulting in Fano- or electromagnetically induced transparency (EIT)-like profile in the scattering spectrum.

Resonance modes in stereometamaterial of square split ring resonators connected by sharing the gap.

Stereometamaerials can fully utilize the 3D degrees of freedom to exploit the coupling and hybridization between multiple split ring resonators (SRRs), enabling more extraordinary resonances and properties over their planar counterparts. Here we propose and numerically study a kind of structure based on connected SRRs sharing their gap in a rotational fashion. It is shown that there are three typical resonance modes in such cage-like SRR (C-SRR) stereometamaterial in the communication and near infrared range.

Angiopoietin1 inhibits mast cell activation and protects against anaphylaxis.

Since morbidity and mortality rates of anaphylaxis diseases have been increasing year by year, how to prevent and manage these diseases effectively has become an important issue. Mast cells play a central regulatory role in allergic diseases. Angiopoietin1 (Ang-1) exhibits anti-inflammatory properties by inhibiting vascular permeability, leukocyte migration and cytokine production.

Multiple reversals of optical binding force in plasmonic disk-ring nanostructures with dipole-multipole Fano resonances.

We study the optical far-field and near-field characteristics, and the optical force effects of plasmonic disk-ring nanostructures. There are multiple Fano features resulting from the scattering interferences of the hybridized modes from the disk's dipole and the ring's higher-order modes. In particular, it is found that the optical binding force between the disk and the ring shows multiple sign reversals spectrally, from the dipole-quadrupole regime up to the dipole-decapole regime.

A robust and dither-free technique for controlling driver signal amplitude for stable and arbitrary optical phase modulation.

We propose a robust and dither-free technique using a delay line interferometer, a balanced detector and simple signal processing to adjust the amplitude of the driver signal of an optical phase modulator automatically for stabilizing the modulated phase of an optical carrier at any arbitrary value. The technique is analytically shown to be robust against practical device imperfections. A stable 45 degrees phase shift with deviation less than ± 0.

A triple function linear fiber laser with passive mode-locking and continuous-wave single-wavelength and multiwavelength lasing.

We propose a fiber laser that can operate with passive mode-locking pulse output, continuous single-wavelength emission, and continuous multiwavelength emission. It consists of a nonlinear optical loop mirror (NOLM) in a linear cavity. The NOLM is used to induce different kinds of intensity-dependent feedback, which determine the operation mode of the laser.

[Cytological study on osteoblasts and in-situ setting calcium phosphate cements].

Objective: To evaluate biocompatibility of three kinds of self-developed injectable calcium phosphate cements (CPCs): chitosan microspheres/CPC, β-tricalcium phosphate (β-TCP)/CPC, and K(+)/CPC and the viability of the osteogenic cells cultured with CPC pastes and discs for 10 days.

Methods: The rabbit marrow stromal cells (rMSCs), isolated from rabbit bone marrow with density gradient centrifugation and flow cytometer, were cultured, expended and induced into osteoblasts. Alizarin red staining was used to determine the function of ossification.

Average capacity optimization in free-space optical communication system over atmospheric turbulence channels with pointing errors.

A model is proposed to study the average capacity optimization in free-space optical (FSO) channels, accounting for effects of atmospheric turbulence and pointing errors. For a given transmitter laser power, it is shown that both transmitter beam divergence angle and beam waist can be tuned to maximize the average capacity. Meanwhile, their optimum values strongly depend on the jitter and operation wavelength.

A new cytotoxic flavonoid from the fruit of Sinopodophyllum hexandrum.

Constituents of the fruit of Sinopodophyllum hexandrum (Royle) Ying (Sinopodophylli Fructus) were investigated. A new flavonoid, 8,2'-diprenylquercetin 3-methyl ether along with 9 known compounds were isolated and identified. Among them, the new compound 8,2'-diprenylquercetin 3-methyl ether exhibited cytotoxic activities against MDA-231 and T47D breast cancer cell lines, quercetin, kaempferol and rutin were isolated from Sinopodophylli Fructus for the first time.

[Immune regulating activity of a novel organoselenium compound ethaselen-1 in C57/BL mice].

Objective: To detect the Immune regulating activity of ethaselen-1 (Eb1), a novel organoselenium compound, in C57/BL mice transplanted with Lewis lung cancer(LLC).

Methods: The LLC transplanted C57/BL mice models were established, and the mice was randomly divided into four groups, including high dose Eb1 group (25.0 mg/kg),low dose Eb1 group (12.