- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Topological Quantum Optics Using Atomlike Emitter Arrays Coupled to Photonic Crystals
摘要： We propose an experimentally feasible nanophotonic platform for exploring many-body physics in topological quantum optics. Our system is composed of a two-dimensional lattice of nonlinear quantum emitters with optical transitions embedded in a photonic crystal slab. The emitters interact through the guided modes of the photonic crystal, and a uniform magnetic field gives rise to large topological band gaps, robust edge states, and a nearly flat band with a nonzero Chern number. The presence of a topologically nontrivial nearly flat band paves the way for the realization of fractional quantum Hall states and fractional topological insulators in a topological quantum optical setting.
关键词： Chern number,quantum emitters,fractional quantum Hall states,photonic crystals,topological quantum optics
更新于2025-09-23 15:21:01
-
Improving efficiency and stability of colorful perovskite solar cells with two-dimensional photonic crystals
摘要： Colorful solar cells have been much sought after because they can generate electricity and concurrently satisfy ornamentation purposes. Owing to their outstanding power conversion efficiency and flexibility in processing, perovskite solar cells (PSCs) have the great potential to become both efficient and aesthetically appealing. Here, we specially devise and fabricate two novel electron transport layers (ETLs) for PSCs with two-dimensional (2D) photonic crystal structures, namely the 2D inverse opal (IO) structured SnO2 (IOS) and SnO2-TiO2 composite (IOST), using the template-assisted spin-coating method. The synergistic structure and material modifications to the ETLs lead to a number of unique features, including the remarkable electron transfer ability, vivid colors and good protection to the infiltrated perovskite films. Furthermore, the IOS and IOST ETLs are effectively incorporated into the CH3NH3PbI3-based PSC devices that deliver the best efficiency of 16.8% with structural colors.
关键词： structural colors,two-dimensional photonic crystals,SnO2,electron transport layers,TiO2,perovskite solar cells
更新于2025-09-23 15:21:01
-
[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Efficient Characterization of Topological Photonics Using the Broadband Greena??s Function
摘要： A novel method is developed in this paper to characterize the band diagram and modal ?elds of gyromagnetic photonic crystals that support topolgoical one-way edge states. We exploy an integral equation based method that utilizes the broadband Green’s function as the kernel. The broadband Green’s function is a hybrid representation of the periodic lattice Green’s function that includes an imaginary wavenumber component represented in exponentially decaying spatial series and a reminder in fast converging Floquet plane wave expansions. Special boundary conditions govern the ?elds across the interface of the gyromagnetic scatterers, leading to surface integral equations (SIEs) that involve three components including the pilot ?eld, its normal derivative and its tangential derivative. To reduce the independent number of unknowns, roof-top basis functions and the Garlerkin’s method are used to discretize the SIEs into matrix equations. The broadband Green’s function allows converting the discretized SIEs into a linear eigenvalue problem of a small size. The eigenvalues and eigenvectors of the linear eigenvalue problem are directly related to the band solutions and modal ?elds of the photonic crystal. The proposed approach is an e?ective method to characterize wave interactions with periodic scatterers using integral equations. The solutions of the presented approach are compared against Comsol simulations for various cases to show its accuracy and e?ciency.
关键词： topological photonics,surface integral equations,broadband Green’s function,linear eigenvalue problem,gyromagnetic photonic crystals
更新于2025-09-23 15:21:01
-
Terahertz refractive index sensor based on the guided resonance in a photonic crystal slab
摘要： The optical properties of a photonic crystals slab (PCS) are highly sensitive to environmental variation. PCS thus are an attractive platform for sensing application. We numerically demonstrate a terahertz refractive index sensor based on the guided resonance in a two-dimensional PCS. The PCS consists of a square lattice of air holes in a silicon slab fabricated on a quartz substrate. By varying each structural parameter systematically, we study the dependence of the resonance located around 0.508 THz on the structural parameters of PCS, and then optimize the structural parameters of PCS for a higher sensitivity. We apply the PCS sensor to detect the refractive index of analytes. The sensitivity of the sensor reaches 23.08 GHz/RIU for the resonance located around 0.508 THz. Our results provide insight into the future terahertz spectroscopy for sensing detection.
关键词： Terahertz,Sensor,Photonic crystals,Guided resonance
更新于2025-09-23 15:21:01
-
Photonic Crystal Enhanced SERS Detection of Analytes Separated by Ultrathin Layer Chromatography Using a Diatom Frustule Monolayer
摘要： Diatoms are single-celled algae that biologically fabricate nanostructured silica shells with ordered pore arrays called frustules that resemble a 2D photonic crystal. A monolayer of Pinnularia frustules isolated from cell culture is deposited on a glass substrate and then conformally coated with silver nanoparticles (AgNPs) to serve as a nanostructured thin film for ultrathin layer chromatography (UTLC). Malachite green and Nile red are resolved in toluene mobile phase and the separated analytes are profiled micro-Raman spectroscopy, where plasmonic AgNPs provide surface-enhanced Raman scattering (SERS). The AgNP-diatom frustule monolayer improves SERS detection of malachite green by an average factor of 1.8 ± 0.1 over the plasmonic AgNP layer on glass. Analysis of hot spots on the AgNP-diatom frustule monolayer reveals that nearly 20% of the SERS active area intensifies the SERS signal at least tenfold over the SERS signal for AgNP on glass. Diatom-SERS enhancement is attributed to guided-mode resonances of the Raman laser source, which in turn further enhances the localized surface plasmonic resonance from AgNPs. Overall, the AgNP-diatom frustule monolayer thin film is a new functional material that uniquely enables separation of analytes by UTLC, quantitative SERS detection of separated analytes, and photonic enhancement of the SERS signals.
关键词： ultrathin layer chromatography,Raman,diatoms,surface-enhanced Raman scattering (SERS),photonic crystals
更新于2025-09-23 15:21:01
-
Photonic transmission spectra in graphene-based Gaussian random multilayers
摘要： The light-matter interaction is a very active and attractive research field and it is the basis of the photonic devices based on the generation, processing and storage of photons. In this work, we theoretically study the propagation of electromagnetic waves in one-dimensional photonic crystals consisting of two different dielectric slabs (silicon dioxide and titanium dioxide) separated by graphene. The spatial arrangement of the slabs is periodic, but we introduce randomness by using a Gaussian distribution of thickness with a specific standard deviation σ. The well-known transfer-matrix method is used as the mathematical approach. Our main goals are to investigate how the presence of such randomness can change the light transmission spectra and the emergence of robust photonic band gaps. For a given angle of incidence, our numerical results show that the two lowest frequency bandgaps are insensitive to the influence of the Gaussian distribution. Those band gaps emerge from two different mechanisms: one is due to the presence of graphene, while the other is due to the Bragg’s scattering. A strong transmission dependence on the standard deviation σ is also observed in our numerical results. More interesting, for the transversal magnetic case (angle of incidence θ ? 60°) the system can be adjusted to present transmission coefficient near to 1 and work like a perfect transparent media, what is useful for technological applications.
关键词： Electromagnetic waves propagation,Light waves transmission,Graphene,Photonic crystals,Random multilayers
更新于2025-09-23 15:21:01
-
Photoactive Functional Soft Materials (Preparation, Properties, and Applications) || A Photoresponsive Multi-Bilayered Film for a Tunable Photonic Crystal
摘要： Over the last half‐century, advances in science based on the evolution of semiconductor physics and transistor electronics have greatly influenced the development of our lives. The key to this was the ability to design crystalline materials that tailor the conduction properties of electrons to suit diverse applications. More recently, the optical communication revolution has shifted the frontier in high‐speed, multiplex, and wide‐bandwidth information processing from electrons to photons, a shift that demands a new kind of synthetic soft material to mold the gigabits. To address this need, recent research has suggested a way to tailor the propagation of light much like that of electrons, via the creation of periodic optical media dubbed photonic crystals (PCs).
关键词： azobenzene,photonic crystals,multi‐bilayered film,photoresponsive,tunable
更新于2025-09-23 15:21:01
-
DOUBLY-PERIODIC PHOTONIC CRYSTALS: SPECTRAL PROBLEMS ANALYSIS
摘要： The present work is devoted to the clari?cation of the conditions necessary for step-by-step justification of the possibility of reduction of the homogeneous system of linear algebraic equations for the spectral problems of 2-D photonic crystals by the plane waves method. The issues related to the algorithms and the numerical solutions of these spectral problems are analyzed. The possibility of analytical regularization is investigated, and the ways to improve the convergence of the obtained results are identi?ed.
关键词： spectral problems,plane waves method,photonic crystals,convergence,analytical regularization
更新于2025-09-23 15:21:01
-
Two Birds with One Stone: Manipulating Colloids Assembled into Amorphous and Ordered Photonic Crystals and Their Combinations for Coding-Decoding
摘要： Photonic crystals including amorphous and ordered photonic crystals (APCs and OPCs) show wide applications in color displays, sensors, and pigments. The fabrication of APCs and OPCs in one method is highly desired, however, it remains a big challenge due to the lack fine control the of the assemble behavior of the colloids. Herein, an efficient surface charge assisted colloidal assembly (SCACA) is developed to fabricate APCs with noniridescent structural colors and OPCs with iridescent colors by the co-assembly of aminated silica particles and nanosized carbon black (CB) in solution with different pH value. The surface charge of the particle is demonstrated to be the key to manipulate the assembly behavior of the particles, thus, the structure, defect, reflection intensity, and angle in/dependent structural color of the photonic crystals can be precisely controlled. Compared with previous strategies, SCACA is considerable simple and efficient in preparing APCs and OPCs which makes the fabrication more controllable, convenient and scalable. Moreover, through combing the noniridescent and iridescent structural colors of APCs and OPCs, a single color and multicolor based coding-decoding system are developed, in which the structural colors, numbers, positions, and angle in/dependency of codes can be hided and recognized by naked eyes at varied viewing angles. This work provides a new insight for precise manipulating the assembly of the colloids into APCs and OPCs, and extends their combined applications in anti-counterfeiting and information storage.
关键词： Surface charge assisted colloidal assembly,Photonic crystals,Coding-decoding system,Ordered photonic crystals,Amorphous photonic crystals
更新于2025-09-23 15:19:57
-
Self-assembled binary photonic crystals under the active confinement and their light trapping
摘要： The self-assembly of oppositely charged colloidal ellipsoids and spheres under the active con?nement is ?rstly proposed to achieve long-range ordered photonic crystals. Compared with the conventional passive con?nement, a characteristic of the active con?nement is that boundaries are movable. Our Brownian dynamics simulations show that dynamic steady structures, similar to quasi-2D colloidal crystals, can be obtained under the strong con?nement when the two boundaries periodically oscillate together. The in-plane structures can be regulated by changing the charge ratio of the two kinds of particles. These dynamic steady structures are determined by the minimum electrostatic energy with the aid of increased mobility of con?ned particles, which are not available in equilibrium. Numerical simulations verify that light can be perfectly con?ned in this dielectric binary photonic slab without any radiation, which corresponds to a typical optical bound state with divergent lifetime and ultrasharp spectral pro?le. Given the changeable geometry of this photonic slab, the trapped optical ?eld might be applicable to enhanced light-matter interactions. In addition, for thicker layers, layer-by-layer ordered structures occur spontaneously driven by the active con?nement, while no global order in the passive con?nement. Our results show that the boundary motion can become an important factor a?ecting self-assembled structure and function.
关键词： colloidal crystals,light trapping,active con?nement,photonic crystals,self-assembly
更新于2025-09-23 15:19:57