Tunable multi-function broadband splitter with optical bistability based on surface plasmon

A tunable multi-function broadband splitter consisted of a silver film, Kerr medium and a silver grating sandwiched between linear dielectrics waveguides is proposed and numerically investigated. This splitter can realize the functions of the beam splitter, the polarization splitter and wavelength beam splitter. This surface plasmon based device provides a unique approach for polarization sensitive manipulation of light in an integrated circuit and will be essential for future classical and quantum information processes.     

基于表面等离子体效应的光开关研究现状和进展

目前表面等离子体(surface plasmons, SPs)效应在光传感、光存储及生物光子学等领域的应用前景受到了广泛关注,通过计算模拟或实验基于SPs效应的光开关也层出不穷.文章较为系统地介绍了各种基于SPs效应的光开关原理和优缺点,对SPs全光开关做了重点介绍.     

局域表面等离激元

局域表面等离激元使得贵金属纳米颗粒具有丰富的光学性质,其应用涵盖能源、生物医学、安全、信息、超材料等诸多领域。文章简要介绍局域表面等离激元的基本性质、贵金属纳米结构中的局域表面等离激元共振耦合以及具有局域表面等离激元特性的贵金属纳米结构的一些重要应用。     

光栅光学双稳态

本文报道了一种光栅光学双稳态装置.利用改变一对对称光栅间相对位移,实现了对透过光强的周期性调制.将这样的系统作为传输部分,分别用He-Ne激光和普通白光完成了光学双稳实验.实验结果与理论分析相符.     

Airy plasmons: non‐diffracting optical surface waves

Airy beams represent an important class of non‐diffracting waves which can be realized on a flat surface. Being generated in the form of surface‐plasmon polaritons, such Airy plasmons demonstrate many remarkable properties: they do not diffract while propagating along parabolic trajectories, and they recover their shape after passing through obstacles. This paper reviews the basic physics of Airy plasmons in both paraxial and non‐paraxial cases, and describes the experimental methods for generation of Airy surface waves on metal surfaces, including a control of their trajectories, as well as the interference of Airy plasmons and hot‐spot generation. Many unusual properties of Airy plasmons can be utilized for useful applications, including plasmonic circuitry and surface tweezers. Picture: Observation of two colliding Airy plasmons.     

表面等离子体增强氧化锌纳米带发光特性的研究

利用简单的化学气相沉积方法在低温下高产量地合成了ZnO纳米带, 并利用磁控溅射对样品进行表面修饰, 制备了Au-ZnO复合纳米带. 通过扫描电镜、透射电镜及微区拉曼等手段系统地研究了表面修饰对ZnO 纳米材料发光性能的影响.结果表明, 在ZnO纳米带上溅射Au纳米颗粒, 可有效增强其近带边发光并使可见发光强度发生淬灭, 从而增强ZnO纳米带的发光性能. ZnO纳米带发光增强因子η最大可达到85倍. 基于Au纳米颗粒的散射、吸收、Purcell增强因子, 以及Ostwald熟化理论, 又进一步探讨了Au-ZnO复合材料的发光机制. 采用表面等离子体耦合的方法可以有效地提高光电半导体器件的发光效率. 关键词： 表面等离体子 光致发光 氧化锌     

损耗对表面等离子体激元压缩态的影响

表面等离子体激元是金属表面电子集体振荡,它以波的形式在金属和介质之间的界面中传播.近期Huck等证明等离子体激元可以处在压缩态,本文利用量子光学的热库理论,研究金波导损耗对表面等离子体激元压缩态的影响,并对Huck等的实验结果给与理论解释. 关键词： 表面等离子体激元 压缩态 热库理论     

截面形状对快电子激发纳米双线表面等离激元的影响

采用边界元方法研究了快电子在金属纳米双线中激发间隙表面等离激元(SPP)的性质,比较了在不同横截面形状(包括圆形、尖劈形和不规则形状)下电子所激发SPP的不同.研究表明:在以上波导结构中,快电子都能激发具有较长传播距离和较好局域性的低阶单级-单级耦合的间隙等离激元模式;同时通过对波导无量纲价值参数的比较,发现快电子在纳米双线中激发间隙等离激元对双线波导的横截面形状要求不高,横截面形状真正影响的是高阶等离激元模式的激发,而且快电子在截面形状为尖劈的双线波导中能激发局域性更强的间隙SPP.该研究将对实验中利用 关键词： 表面等离激元 间隙模式 金属纳米波导     

Theoretical study of photon emission from single quantum dot emitter coupled to surface plasmons

Motivated by the recent pioneering advances on nanoscale plasmonics and also nanophotonics technology based on the surface plasmons (SPs), in this work, we give a master equation model in the Lindblad form and investigate the quantum optical properties of single quantum dot (QD) emitter coupled to the SPs of a metallic nanowire. Our main results demonstrate the QD luminescence results of photon emission show three distinctive regimes depending on the distance between QD and metallic nanowire, which elucidates a crossover passing from being metallic dissipative for much smaller emitter-nanowire distances to surface plasmon (SP) emission for larger separations at the vicinity of plasmonic metallic nanowire. Besides, our results also indicate that, for both the resonant case and the detuning case, through measuring QD emitter luminescence spectra and second-order correlation functions, the information about the QD emitter coupling to the SPs of the dissipative metallic nanowire can be extracted. This theoretical study will serve as an introduction to understanding the nanoplasmonic imaging spectroscopy and pave a new way to realize the quantum information devices.     

富勒烯分子的光学双稳性

本文采用非线性法布里-珀罗腔的全光光学方法,在C_(60)/C_(70)薄膜中首次观测到双稳开关现象,其开关时间为10ns.     

光学双稳性的强迫振动模型

本文提出一个新的光学双稳性模型.基于平均场近似,慢变振幅近似和绝热近似的思想,把光学双稳系统看成一个“黑箱”,类比非线性振动理论,指出不同的光学双稳过程(包括不同的工作物质和不同的腔(F-P腔或环腔)),能用一个恰当的强迫振动方程统一地描述.方程中所包含的都是可测量的宏观参量,使得可能直接用实验拟合,与理论结果进行定量对照.用振动理论的方法,把方程演变成自治方程组,从而方便地得到光学双稳性稳态和动态解的一般形式.并用若干已报道的具体例子验证了这个模型的普适性.     

高吸收ZnSe多晶无镜光学双稳的实验观测

本文对具高吸收的ZnSe多晶材料的增加吸收型光学双稳性进行了实验观测,发现在介质的吸收远高于过去提出的理论判据时,仍能获得双稳输出,并测定了阈值开关功率与光斑尺寸及样品厚度的关系.采用分层模型分析实验结果,定性地解释了实验现象.     

Influence of frequency noise on nascent hysteresis in optical bistability

We study the influence of frequency noise on optical bistability in the neighborhood of the critical point where the hysteresis loop appears. We show that when the transmitted field evolves on a faster time scale than that of the noise, the hysteresis loop shifts toward lower values of the incident pumping field.     

Controllable optical bistability of Bose-Einstein condensate in an optical cavity with a Kerr medium

We study the optical bistability for a Bose-Einstein condensate of atoms in a driven optical cavity with a Kerr medium. We find that both the threshold point of optical bistability transition and the width of optical bistability hysteresis can be controlled by appropriately adjusting the Kerr interaction between the photons. In particular, we show that the optical bistability will disappear when the Kerr interaction exceeds a critical value.     

Controllable optical bistability and multistability in a rare-earth-ion-doped optical fiber

We investigated the optical bistability and multistability in an Er³⁺-doped ZrF₄–BaF₂–LaF₃–AlF₃–NaF optical fiber inside an optical ring cavity. It is found that the optical bistability and multistability can be easily controlled via adjusting properly the parameters of the corresponding system. Our scheme may provide some new possibilities for technological applications in optoelectronics and optical-fiber communication.     

左手材料与非线性光学材料界面处的内光学双稳态

从理论及数值上研究了左手材料与传统非线性材料界面处的电磁波性质。发现在界面处出现一种新的现象——光学双稳态。入射光强、入射角以及左手材料与非线性材料的磁导率比值强烈的影响光学双稳态的行为。比较了不同的电磁模式对双稳态行为的影响。结果表明在相同的参数下，TE模式比TM模式更容易获得光学双稳态。     

Controllable optical bistability of Bose—Einstein condensate in an optical cavity with Kerr medium

We study the optical bistability for a Bose-Einstein condensate of atoms in a driven optical cavity with Kerr medium. We find that both the threshold point of optical bistability transition and the width of optical bistability hysteresis can be controlled by appropriately adjusting the Kerr interaction between the photons. In particular, we show that the optical bistability will disappear when the Kerr interaction exceeds a critical value.     

Numerical analysis of waveguide-enhanced optical bistability

We present the results of a simulation study of a multilayer structure for which strongly enhanced (resonant) electric fields are produced at the surface of, and in the interior of, a planar waveguide which is evanescently coupled to an incoming beam in a prism geometry. The resulting field enhancements can far exceed those associated with the well-known surface plasmon resonance in a typical silver film excited in the conventional attenuated total reflection geometry. Simulations are performed for optical bistability for the case of a typical YAG laser beam coupled to a zinc oxide (ZnO) waveguide, demonstrating that the effect should occur for reasonable values of the parameters involved.     

Spin-controlled directional launching of surface plasmons at the subwavelength scale

In this paper, we demonstrate a spin-controlled directional launching of surface plasmons at the subwavelength scale.Based on the principle of optical spin's effect for the geometric phase of light, the nanostructures were designed. The inclination of the structures decides the spin-related geometric phase and their relative positions decide the distance-related phase. Hence, the propagation direction of the generated surface plasmon polaritons(SPPs) can be controlled by the spin of photons. Numerical simulations by the finite difference time domain(FDTD) method have verified our theoretical prediction. Our structure is fabricated on the Au film by using a focused ion beam etching technique. The total size of the surface plasmon polariton(SPP) launcher is 320 nm by 180 nm. The observation of the SPP launching by using scanning near-field optical microscopy is in agreement with our theory and simulations. This result may provide a new way of spin-controlled directional launching of SPP.