基片缺陷与磁光盘原始误码

分析了基片缺陷导致磁光盘产生原始误码的原因。首次建立了磁光读出光场与基片杂质特性的数学模型，利用数值分析方法研究了读出信号畸变、误码长度与杂质特性的关系。分析结果表明，一定大小的基片杂质是否产生误码，与杂质距记录层的距离、杂质距读写光斑的距离以及读出阈值电平等因素有关。     

Critical phenomena in a disc-percolation model and their application to relativistic heavy ion collisions

By studying the critical phenomena in continuum-percolation of discs, we find a new approach to locate the critical point, i.e. using the inflection point of P∞ as an evaluation of the percolation threshold. The susceptibility, defined as the derivative of P∞, possesses a finite-size scaling property, where the scaling exponent is the reciprocal of v, the critical exponent of the correlation length. A possible application of this approach to the study of the critical phenomena in relativistic heavy ion collisions is discussed. The critical point for deconfinement can be extracted by the inflection point of PQGP -- the probability for the event with QGP formation. The finite-size scaling of its derivative can give the critical exponent v, which is a rare case that can provide an experimental measure of a critical exponent in heavy ion collisions.     

Surface optical phonon—assisted electron Raman scattering in a semiconductor quantum disc

We have carried out a theoretical calculation of the differential cross section for the electron Raman scattering process associated with the surface optical phonon modes in a semiconductor quantum disc.electron states are considered to be confined within a quantum disc with infinite potential barriers.The optical phonon modes we have adopted are the slab phonon modes by taking into consideration the Frohlich interaction between an electron and a phonon.The selection rules for the Raman process are given.Numerical results and a discussion are also presented for various radii and thicknesses of the disc,and different incident radiation energies.     

532nm激光器光存储聚焦技术研究

在光存储系统中，为了保证存取信息所用的激光束准确地聚焦在记录介质表面上，必须具有精密自动调焦系统，该系统包括激光光源，扩束准直和整形光学元件，光学物镜，光电探测器，以及能上下运动的双轴力矩器。其中执行机构是在磁场中的双轴力矩器，线圈中电流不同时双轴力矩器拖动聚焦物镜上下移动，达到聚焦的目的。此过程中，位置探测器探测到焦点离存储介质表面的距离参数，并转化成聚焦误差信号，由此聚焦误差信号对物镜相对于存储介质的距离进行修正，从而使得激光束能准确地聚焦在介质表面上。结合532nm绿光，采用CDRW可擦写光盘，得到了约500nm的光存储斑。     

1960年5月16日：梅曼建造了第一部可运作的激光器

21 世纪,激光的使用无所不在,形成了每年几十亿美元的产业,随便举几个例子,电信、数字光盘播放器(DVD player)、结账扫描机、切割及焊接器、眼睛手术、刺青移除、牙科和医学等都是激光的市场。     

Grain size and its distribution in NiTi thin films sputter-deposited on heated substrates

Grain size and its distribution in NiTi thin films sputter-deposited on a heated substrate have been investigated using the small angle x-ray scattering technique. The crystalline particles have a small size and are distributed over a small range of sizes for the films grown at substrate temperatures 370 and 420℃. The results show that the sizes of crystalline particles are about the same. From the x-ray diffraction profiles, the sizes of crystalline particles obtained were 2.40nm and 2.81nm at substrate temperatures of 350 and 420℃, respectively. The morphology of NiTi thin films deposited at different substrate temperatures has been studied by atomic force microscopy. The root mean square roughness calculated for the film deposited at ambient temperature and 420℃ are 1.42 and 2.75nm, respectively.     

光盘信息符散斑图的统计特性研究

提出了一种用激光散斑测量光盘信息符统计特性的方法.利用散斑统计理论中衍射散斑场的平均对比度与散射屏表面粗糙度近似成线性关系,把光盘等效为弱散射屏,对未刻录、刻录及存在缺陷的CD-R光盘不同区域形成的衍射散斑图进行了对比研究.实验结果表明,该方法具有可量化、全场测量的优点,能够表征光盘信息符的某些统计特性,这为测量光盘刻录质量提供了一种新的方法和途径.     

光盘与光存储技术简介

本文较全面地介绍了各类光盘的结构、性能、记录原理和加工过程,特别注意介绍光盘技术中涉及到的物理原理。     

光盘高频信号的物理实验设计与测量

应用电子技术理论,利用旧光驱和模拟示波器,演示了光盘高频信号形成的“眼图”,并测得了高频信号的最高电平(Itop),归一化I11值,归一化I3值,分辨率(RES)、对称性(SYM)等参数.此演示实验装置简单易于操作,体现了日常生活中的高新技术与大学物理的联系,可用于大学物理光学部分的演示实验教学和特性分析.