Influence of Excitation Pulse Width on the Second-Order Correlation Functions of the Exciton-Biexciton Emissions

We investigate theoretically the population dynamics and the second-order correlation functions of photon emissions from the biexciton-exciton system of a single quantum dot with excitation from pulses to continuous wave. The dynamic equations of the correlation functions are deduced by applying quantum regression theorem to optical Bloch equations. The influences of excitation pulse width on the correlation function have been discussed in detail.     

Surface Plasmon Resonance and Field Enhancement of Au/Ag Alloyed Hollow Nanoshells

We investigate the nanostructure, surface plasmon resonance （SPR） absorption and nonlinear enhancement of Au/Ag alloyed hollow nanoshells prepared by the replacement reaction of Ag nanoparticles in a HAuCI4 aqueous solution. As the volume of HAuCl4 increases from OmL to 0.S mL, the SPR band of the Au/Ag alloyed nanoshells is tuned from 430nm to 780nm, and the third-order nonlinear optical susceptibility is enhanced nearly by an order of magnitude, which indicates a large enhancement of local field in the Au/Ag alloyed hollow nanoshells with hole defects.     

Effect of temperature on the evolution of bright and dark screening—photovoltaic spatial solitons

We investigate theoretically the temperature effects on the evolution of both bright and dark screening-photovoltaic optical spatial solitons in biased photovoltaic-photocefractive crystals in the case of neglecting the diffusion process.For a stable bright or dark screening-photovoltaic soliton originally formed in a crystal at a given temperature,when the crystal temperature changes,it will evolve into another stable screening-photovoltaic soliton if the change is quite small,whereas it will become unstable or break down if the temperature change is large enough.The spatial shape of a stable screening-photovoltaic soliton can be reshaped by appropriately adjusting the crystal temperature.     

Coupling and stability of bright holographic soliton pairs

The coupling effect and stability property of symmetric bright holographic soliton pairs have been investigated numerically. Results show that when any one of the two solitary beams from a pair is perturbed in amplitude or width, both beams will be affected by such a perturbation via the coupling effect between the beams, thus resulting in both beams propagating in the medium without a constant shape; however, these two solitary beams are still stable against small perturbations. When both solitary beams from a pair are perturbed simultaneously in amplitude, for some given absolute values of the perturbations, the two beams are stable against these perturbations if both beams are perturbed with the same sign, whereas are unstable with the different signs. When the two beams are simultaneously perturbed in width, both beams exhibit their stability property similar to that when only one beam is perturbed no matter whether both perturbations have the same or different signs.     

主客体式光折变聚合物中空间明孤子的动态演化特性

研究了主客体式光折变聚合物中空间明孤子的动态演化特性,讨论了振幅微扰和宽度微扰对其传播特性的影响.结果表明,入射波为明孤子波时,能够在聚合物中稳定直线传播 在较小微扰情况下,孤子波经短距离传播后能够演化为明孤子波 当微扰比较大时,光波不能在聚合物中稳定传播,而是呈现周期性震荡现象 关键词： 光折变效应 光折变聚合物 空间孤子     

Au-Ag复合纳米阵列的制备及其等离激元共振吸收特性

利用二次阳极氧化法在硫酸体系中制备了多孔氧化铝模板,用交流法在模板中沉积了Au-Ag复合纳米阵列,并研究了其表面等离激元共振吸收特性.和单独的Au、Ag纳米线阵列不同,Au-Ag复合纳米阵列的紫外可见吸收光谱中有两个横向吸收峰,一个纵向共振吸收峰.Au-Ag复合纳米阵列的纵向等离共振波长可以通过改变Ag的生长时间进行有效调节.实验结果发现,Au沉积对后续沉积Ag的最佳沉积电压有影响.     

Population Swap of a Pair of Quantum Dots Coupling to a Plasmonic Nanocavity

We theoretically design a single-mode plasmonic ring nanocavity. Based on the plasmonic cavity, the exciton dynamics between two identical quantum dots （QD-p, QD-q） coupled to the nanocavity are investigated. It is shown that the coupling factors gi （i = p, q） between QD-i and surface plasmons are both equal to 12.53meV in our model and exeiton population swap between the two QDs can be realized. The periods and amplitudes of population oscillations can be modified by the coupling factors. Our results may have potential applications in quantum information and quantum computation on a chip.     

One- and Two-Photon Excited Fluorescence of CdSe and CdSe/ZnS Quantum Dots in n-Hexane

One- and two-photon absorption and excited fluorescence of the CdSe and the core-shell structure CdSe/ZnS quantum dots （QDs） in n-hexane is investigated. The linear and nonlinear absorption coefficients are measured and the two-photon-absorption cross sections of the QDs are also obtained. For both one-photon fluorescence and two-photon fluorescence, the emission efficiency of CdSe/ZnS is much higher than that of CdSe, originating from the effective surface passivation of the core-shell structure.     

Photoluminescence from Nd Doped Anodic Aluminium Oxide

We prepare Nd doped anodic aluminium oxide （Nd：AAO） template by using Nd doped aluminium foils through two-step anodization processes. Photoluminescence （PL） from the Nd：AAO template with the annealing temperature higher than 400℃ is observed, and the PL intensity enhanced with the increasing annealing temperature is found. We investigate the crystallization of Nd：AAO template and the excitation wavelength dependence of PL intensity, showing that the PL results from the Nd doped in the template. The approach presented may probably facilitate the fabricating of AAO with good light-emitting property, which can be used in fabrication of multifunctional nanosized films and may find applications in photonic devices.     

无偏压的串联光折变晶体回路中高斯光束传播特性调节

根据串联光折变晶体回路中独立空间孤子对理论,研究了明暗孤子对之间的相互依赖特性.假设一束暗孤子波和一束高斯光束分别入射到回路中两块晶体上,利用数值计算方法讨论了改变其中暗孤子光束的强度对高斯光束在另外一个晶体中传播特性的影响.结果表明,调节暗孤子的强度能够影响高斯光束的传播特性,可以决定高斯光束在晶体中是否能够演化为稳定传播的明孤子波 关键词： 非线性光学 光折变效应 光折变空间孤子对 高斯光束