c向切割LiNbO_3∶Fe晶体中光折变光散射

提出了一个新的理论机理 :c向切割LiNbO3∶Fe晶体中光折变背向光散射是由光生伏特电流的不均匀性引起的 ,并经过理论计算 ,比较成功的解释了实验观察到的各种现象     

铌酸锂晶体中的分形几何观察

研究了铌酸锂晶体沿c轴的真实生长界面及腐蚀坑模式,在两种情况中均观察到了明显的塞尔宾斯基(Sierpinski)三角垫分形几何特征,两种情况的分形维度通过计算得出均为ln3/ln2≈1.58.     

等径控制系统的改进及在光学级铌酸锂生长中的应用

分析了提拉法晶体生长过程中影响滞后变化的因素,采用传统PID调节器和计算机辅助控制相结合的办法,解决了铌酸锂晶体生长过程中的精确等径控制问题,并在大直径铌酸锂晶体生长应用中取得了满意的效果.生长的76mm直径的铌酸锂晶体,生长条纹问题得到很大改善,光学均匀性提高了一个量级以上.     

c向切割LiNbO3:Fe晶体薄片中的四波混频各向异性光散射

报道了在ｃ向切割ＬｉＮｂＯ₃：Ｆｅ晶体薄片的前向光散射中观察到的一种新的类似鸭蛋形的各向异性衍射光环图样，并且提出了由入射光、强的背向散射光而引起的四波混频各向异性光散射机制，圆满地解释了有关实验结果。 关键词：     

Red Up-Conversion Luminescence Process in Oxyfluoride Glass Ceramics Doped with Er^3＋／Yb^3＋

The phonon-assisted quantum cutting (PQC) model is presumed to clarify the red up-conversion luminescence process in Er^3 /yb^3 co-doped glass ceramics by the excitation and emission spectra. The red up-conversion luminescence of Er^3 ions mainly comes from three-photon absorption by the PQC process when the rare earth ions are doped in the g/ass ceramics and excited by 98Ohm pumped-laser. Er^3 ions absorb three-photons and relax to the ^4G11/2 state and then emit red up-conversion luminescence by the PQC process. The factor coefficient for the relation of pump-laser power and up-conversion intensity (P-I) is found by the analysis of excitation spectra of the red luminescence, which plays a major role to understand the true red up-conversion luminescence process. The new P-I relation is explained by the model of PQC.     

Highly efficient narrow-band plasmonic waveguide filter based on cascaded slot cavities

A novel plasmonic waveguide filter design based on three cascaded slot cavities is proposed. The cascaded nanocavities support a united resonant （UR） mode. Light is trapped in the middle nanocavity at telecom- muaication wavelenEth （1550 rim） when the UR mode exists. This phenomenon leads to the efficient transmittance and high Q factor of the plasmonic filter. The resonant wavelength and Q factor can be easily modulated by the cavity radii and the waveguide width.     

Quantitative analysis of the self-absorption and reemission effects on the emission spectrum of photoluminescence in right-angle excitation–detection configuration

A theoretical approach based on differential radiative transport is proposed to quantitatively analyze the selfabsorption and reemission effects on the emission spectrum for right angle excitation–detection photoluminescence measurements,and the wavelength dependence of the reemission effect is taken into account.Simulations and experiments are performed using rhodamine 6G solutions in ethanol as model samples.It is shown that the self-absorption effect is the dominant effect on the detected spectrum by inducing pseudo red-shift and reducing total intensity;whereas the reemission effect partly compensates for signal decrease and also results in an apparent signal gain at the wavelengths without absorption.Both effects decrease with the decrease in the sample concentration and the propagation distance of the emission light inside the sample.We therefore suggest that diluted solutions are required for accurate photoluminescence spectrum measurements and photoluminescence-based measurements.     

固态源分子束外延法生长InGaP/GaAs异质结构的热力学分析

本文建立了采用分子束外延法制备InGaP/GaAs异质结构的热力学模型,其中考虑了两个重要的因素,由晶格失配引起的内在应力和InP的脱附.所得到的模型与现有实验结果匹配较好.该模型的实验结果表明在InGaP的生长过程中,生长温度,In/Ga束流比及合金组分之间的相互关系,同时也与实验数据相吻合.该模型对于其他气相沉积生长方式也具有一定的适用性.     

Photopolymerization-Induced Two-Beam Coupling and Light-Induced Scattering in Polymethyl Methacrylate

Light amplification due to two-beam coupling is realized in doped polymethyl methacrylate （PMMA） glasses. A coupling gain as large as 14 cm^-1 is obtained. The dynamic behaviour of absorption and light-induced scattering due to the process of photopolymerization are also studied. The results show that the amplification and its dynamic process enable possible applications of PMMA in optical devices.     

Er玻璃近红外区上转换发肖的研究

研究了Er,Yb共掺磷酸盐玻璃的上转换发光.对于在800nm附近的近红外发光进行了分析,认为该发光带是由于三种跃迁引起的,除了常见的4F9/2→4I15/2跃迁以外,还存在着