基于液晶光阀的全息照相控光仪

设计了通过液晶光阀自动调整全息照相物光和参考光辐照比至最佳状态,同时能实现曝光时间自动控制的控光仪.该仪器巧妙运用液晶光阀和硅光电池器件,使测量、调整、自控一体化,从而提高拍摄优质全息图的工作效率.     

粒子与光电材料相互作用的应用基础研究获自然科学奖

据《济南日报》消息，在2006年1月10日召开的全国科技大会上，山东大学物理与微电子学院王克明教授完成的项目“粒子与光电材料相互作用的应用基础研究”获国家自然科学奖二等奖。该项目在离子注入光波导研究领域取得一些原创性成果，对进行跨学科新领域的课题研究具有重要的借     

碳纳米管被“激光镊子”牵鼻走

~~碳纳米管被“激光镊子”牵鼻走@汪道友~~     

Nonlinear Effects for Bose Einstein Condensates in Optical Lattices

Cold atoms and, more recently, Bose-Einstein condensates （BEC＇s） in optical lattices have attracted increasing interest since their first realization. In particular, the formal similarity between the wavefunction of a BEC inside the periodic potential of an optical lattice and of the electrons in a crystal lattice has triggered theoretical and experimental efforts alike. Many phenomena from condensed matter physics, such as Bloch oscillations and Landau-Zener tunneling have been shown to be observable also in optical lattices. An important difference between electrons in a crystal lattice and a BEC inside the periodic potential of an optical lattice is the strength of the self interaction and hence the magnitude of the nonlinearity of the system. Electrons in a metal are almost noninteracting, whereas atoms inside a BEC interact strongly. A＇ perturbation approach is appropriate in the former case while in the latter the full nonlinearity must be taken into account. From this feature new physics is expected. Most experiments to date have been carried out in the regime of shallow lattice depth, for which the system is well described by the mean field Gross-Pitaevskii equation with a periodic potential. Moreover, the nonlinearity induced by the mean-field of the condensate has been shown, both theoretically and experimentally, to give rise to instabilities in certain regions of the Brillouin zone. These instabilities are not present in the corresponding linear system, i.e. the electron system. Experimental and theoretical results on the subject of nonlinear Landau-Zener tunneling and nonlinearity-induced instabilities in a Bose-Einstein condensate interacting with an external periodic potential will be presented.     

一维光学格子孤子的传输特性及控制研究

利用解析和数值方法研究了在具有横向折射率周期性调制的克尔型非线性介质中光学格子孤子的传输，得到了孤子参数的演化方程以及格子孤子的形成和稳定传输的条件.结果表明：当光束的入射角小于某临界角度时，光束可被类似波导形式的路径俘获而稳定传输，该临界角随折射率调制周期、调制深度的增加而增大，且光束越窄临界值越大.此外，线性空间啁啾虽然对光束传输的中心位置没有任何影响，但会导致光束发散从而破坏格子孤子的形成和稳定传输，对此提出了采用特定功率取值来补偿啁啾作用从而形成格子孤子的方案. 关键词： 光孤子 光学格子 光传输 矩方法     

引导探究学习 构建知识网络——研究性学习个案研究

研究课题　圆柱面上的椭圆在圆柱侧面展开图中形状的研究 .本课宗旨　通过探讨圆柱面上的椭圆在圆柱侧面展开图中的形状 ,引导学生综合运用立几、三角、解几等知识分析问题 ,培养学生在知识交汇处发现问题、解决问题的能力 ,帮助学生构建知识网络 .教学过程　1　提出问题图 1　圆柱1 .1　问题 1　平面与圆柱面的交线是什么圆形 ?学生 :圆或椭圆或线段 .老师 :对椭圆这一情形 ,大家直觉感知的结果完全正确 .你能给出逻辑证明吗 ?对此问题 ,学生知其然而不知其所以然 ,“心欲求而不得 ,口欲言而不能” ,认知渴望激起了学生积极探究的冲动 .老…     

一种高信噪比的双光束激光光声光谱仪原理及应用

作为一种新兴的检测手段 ,激光光声光谱技术与其他检测技术相比具有很多优点。本文设计的光声光谱仪用激光做光源 ,有两个光声池 ,分别用来放置参考样品和待测样品 ,输出结果为二者光声信号的比值。利用这一比值 ,可以由参考样品的性能参数方便地求出待测样品的相关性能参数。该光声光谱仪有效地减小了本底吸收噪声的影响 ,提高了信噪比 ,扩大了固体光声理论的应用范围。本文还阐述了该光声光谱仪在定性定量分析中的一些应用     

薄铝埋点等离子体K线光谱半定量诊断

高温等离子体系统中存在等离子体流体力学运动演化过程、离子的离化分布演化动力学过程、高剥离态离子谱发射过程及发射芬光辐射输运过程等，而且高温等离子体系统通常是非平衡系统，所以定量研究高温等离子体系统的发射X光谱和高温等离子体对X光的吸收是一个非常复杂的问题。为了模拟和解释实验测得的激光等离子体发射光谱，提出了一种薄埋点靶：直径为φ200μm厚度为0．1μm的铝点埋在20μm厚的CH膜底衬中，表面再覆盖0．1μm厚CH膜。     

串联双环光微谐振器的滤波特性

详细研究了串联双环光微谐振器的光带通滤波特性，给出了其通带带宽的公式，分析了出／入环光耦合系数和环间光耦合系数对通带特性的影响，计算并特别强调了滤波通带的结构特点，也分析了微环中存在的光损耗对串联双环光微谐振器的滤波特性的影响。     

Experimental Study of Effect of Medium Boundary on Light Distribution in Tissue Phantoms

An experimental method for investigating the effect of medium boundary on distributions of light in the biological tissue phantom intralipid is presented. Measurements of distributions of light in intralipid-10% suspensions at 633 nm are described, in which a narrow collimated beam is incident on the surface of the phantoms and into the different depths inside of the phantoms. The experimental results show that the effect of the boundary of the medium on the curves geometry of light distributions is trivial, but the effect on intensity of scattering light is obvious, the maximal relative change of the energy fluence reaches 53.8% and the position of the peak of the energy fluence curve has a shift of 1.1 mm in the reverse direction of incident light for the phantom with albedo a=0.998, and the effect of the boundary is decreased with the increase of the absorption coefficients of tissue phantoms. The experimental results were analysed by the diffusion theory. These studies will be helpful for further understandings of the relation between the boundary of biological tissue and the distribution of light in tissue.