A new tracking error detection method using amplitude difference detection for signal waveform modulation multi-level discs

The sub-land/sub-pit affects the characteristic of the tracking error signal which is generated by the conventional differential phase detection (DPD) method in the signal waveform modulation multi-level (SWML) read-only disc. To solve this problem, this paper proposes a new tracking error detection method using amplitude difference. Based on the diffraction theory, the amplitude difference is proportional to the tracking error and is feasible to be used for obtaining the off-track information. The experimental system of the amplitude difference detection method is developed. The experimental results show that the tracking error signal derived from the new method has better performance in uniformity and signal-to-noise ratio than that derived from the conventional DPD method in the SWML read-only disc.     

光致变色多阶游程光存储研究

多阶游程存储是一种不改变光学系统而显著提高光存储容量和数据传输率的新方法.介绍了光致变色多阶游程存储原理和实验系统.提出了基于光致变色原理的多阶游程存储数学模型，该模型反映了记录符反射率与曝光功率、曝光时间之间的非线性关系，并在此基础上确定了光致变色多阶游程存储的写策略.基于650nm光致变色材料进行了4阶游程存储的动态实验.结果表明，实验中采用的650nm光致变色材料可用于多阶游程存储，采用的写策略能够有效地使记录信道线性化，利于采用适合线性系统的信号处理方法. 关键词： 多阶游程 光致变色 光存储 写策略     

锂原子高里德伯态跃迁的振子强度和辐射寿命

根据k系数方法[1]，应用最弱受约束电子势模型下的简单解析波函数，系统研究了各种可能节点校正下，锂原子高里德伯态（n～40）间跃迁的振子强度与辐射寿命，得到了对应于各跃迁类的节点校正规则，在这些节点校正规则下，所得振子强度及辐射寿命与可得到的其他作者的结果非常接近，表明了k系数方法对于研究锂原子高里德伯态性质的有效性     

铕与PMBP配合物晶体结构和电子结构的研究

本文测定了 Eu(PMBP) 3 · 2 H2 O的晶体结构 ,该晶体属于单斜晶系 ,空间群 P2 1 / n,a=14 .982 1(1) ,b=14 .75 18(8) ,c=2 4 .4 979(9) ,β=10 1.5 2°,Z=4 ,V=5 30 2 .2 3 ,M=10 0 1.9,Dc=1.2 5 4 g/ cm3 ,μ=12 .315 cm-1 。 Eu与 PMBP及水中的 8个氧原子形成四方反棱柱配位多面体 ,根据选用的模型计算其电子结构 ,分子能量 ,净电荷分布和 Mulliken键级 ,进而讨论了配合物的结构和化学键的特征。实　验　部　分按 Eu(Cl O4) 3 · 2 H2 O中 Eu( )与 HPMBP摩尔比 1∶ 3反应 ,得到配合物固体。置于水与无水乙醇中 ,数周后…     

Improved partial response maximum likelihood method combining modulation code for signal waveform modulation multi-level disc

In this paper, we describe an improved adaptive partial response maximum likelihood （PRML） method combining modulation code tbr signal waveform modulation multi-level disc. This improved adaptive PRML method employs partial response equalizer and adaptive viterbi detector combining modulation code. Compared with the traditional adaptive PRML detector, the improved PRML detector additionally employs illogical sequence detector and corrector. Illogical sequence detector and corrector can aw）id the appearance of illogical sequences effectively, which do not follow the law of modulation code for signal waveform modulation multi-level disc, and obtain the correct sequences. We implement the improved PRML detector using a DSP and an FPGA chip. The experimental results show good performance. The higher efficient and lower complexity can be obtained by using the improved PRML method than by using the previous PRML method. Meanwhile, resource utilization of the improved PRML detector is not changed, but the bit error rate （BER） is reduced by more than 20%.     

一个非晶硅薄膜太阳能电池制备用激光刻线系统

 非晶硅薄膜太阳能电池制备过程中的激光刻线工艺要求刻线宽度在30 μm～50 μm之间,死区范围小于300 μm,刻线深度符合工艺要求。这不仅要求激光器具有较高的光束质量,而且要求光学系统具有较高的成像质量和较宽的焦深。设计了单激光器四分光路的激光刻线系统。采用设计的激光刻线装置,在1 400 mm×1 100 mm×3.2 mm玻璃基板上进行刻线试验,分别得到刻线P1,P2,P3的线宽为35 μm,50 μm和45 μm,死区范围（P1至P3的距离）为287 μm,最终深度分别为0.98 μm,0.24 μm和0.58 μm,刻线宽度和深度均符合薄膜太阳能电池制备工艺要求。     

A Three—dimensional Network Topology in [Mn（N3）2（4,4‘—bipy）]n,Generat

Compound [Mn(N3)2(4, 4'-bipy)]n having three-dimensional structure was obtained with crystallographic data: C10H8N8Mn (Mr=295.16), tetragonal, space group P412121(#99), a=8.220(2), c=16.918(5)(), V=1143.1(5)()3, Z=4, Dc=1.715 g/cm-3, μ=11.07 cm-1, F(000)=596, R=0.042, Rw=0.051, for 590 observable reflections. The special topology structure in the compound occurs from the helical chain consisting of the -Mn-N-N-N-Mn'-unit. The value of χmT decreases with the decreasing of temperature     

Pit Depth and Width Modulation Multilevel Run-Length Limited Read-Only Optical Storage

When the techniques of integrating the variation of the conventional DVD,the high-density multilevel run-length pit depth and width simultaneously are adopted to limited read-only optical storage method is achieved. The dynamic range of readout signal is greatly enlarged in comparison with keeping one parameter varied, and the recording levels number can be obviously increased. The discs can be manufactured using standard photoresist mastering and replication techniques with great compatibility to conventional binary read-only discs. Experimental results show that eight-level read-only optical disc can be realized and the capacity can be increased to 20 GB.     

悬线式物镜力矩器动态特性的仿真实验研究

悬线式物镜力矩器是目前光学头系统中使用最为广泛的力矩器,其动态特性直接决定了光学头的读写性能。基于ANSYS参数化设计语言(APDL)建立了悬线式光学头物镜力矩器的仿真设计平台。通过仿真平台进行了力矩器一阶共振频率和峰值、二阶共振频率和峰值、扭转共振频率、静态灵敏度、动态灵敏度和相位等动态特性参数的仿真实验,仿真计算的结果与实际测量的结果相比,最大相对误差为4.2%。该仿真平台对于二维乃至三维悬线式物镜力矩器的设计和评价都具有重要的指导意义。     

可记录光盘染料旋涂工艺的流动机制研究

染料旋涂是可记录光盘复制中的核心工艺，依据实验给出旋涂工艺的简化模型，并运用旋转圆盘理论分析流体流动，考虑基片上的预刻槽对流动的影响，考虑基片表面和流体间的滑移效应，导出运动方程、边界方程和连续方程，最终导出染料旋涂的控制方程。