蓝光存储——信息化的核心技术

信息化的核心是数字化,数字化的基础是存储。蓝光存储是目前容量最大、最安全、成本最低的存储技术。本文通过蓝光与红光之间的技术比较、蓝光技术具体应用,介绍了蓝光光盘技术及其发展概况,回顾了中国前三代光存储技术产业的发展历程,分析了中国企业冲击第四代、第五代光存储技术的条件和实力。     

光存储技术应用及其发展

在介绍光存储技术原理及应用的基础上,分析了国内外高清晰度光盘技术方案,包括采用红光技术的EVD、NVD、FVD和采用蓝光技术的BD、HDDVD．CBHD。简要介绍了三维光存储技术,并针对我国高清晰度光存储技术的发展进行了分析并提出了几点建议。     

国际要闻

TDK推出200G蓝光存储光盘据EETimes网站报道:日本TDK近期研发成功了存储能力达到200G的单面可记录蓝光光盘,超过现有存储能力达到25G的单层蓝光光盘和50G的双层光盘。公司表示,200G的存储能力是TDK现有100G蓝光原型产品的2倍,可以存储大约18h的高精度视频。TDK走在了蓝光光盘媒体研发的最前沿,已于4月份开始交货25G可重复读写光盘。公司的100G光盘采用了四层25G存储层以达到其存储能力。对于200G光盘,TDK采用了蓝光光盘格式物理极限,在每层存储层上进行33.3G的数据存储,同时还要满足蓝光特征还原的最小容差。据Dow Corning Cor…     

采用不同中间夹层的双记录层磁光光盘热光特性比较

磁光存储技术是一种颇受关注的下一代光存储技术.为提高单个磁光光盘的存储容量,途径之一是采用多值存储、多波长读出技术,实现所谓三维磁光存储.通常使用不同波长的蓝光来实现信号的读写操作.如果不同波长的激光在磁光存储多层膜中产生热场分布的差异较大,将有利于提高读出信号的信噪比.本文结合光学矩阵法及有限元方法分析了中间夹层分别为SiN、GaP时,磁光存储多层膜的热光特性.结果表明在蓝光波段,用GaP层替代传统的SiN中间夹层,将使磁光光盘具有更好的热光特性.     

夏普超分辨光盘可存储100GB数据

夏普公司发展出一种蓝光激光存储技术，其储存信息为现在进入市场的蓝光光盘每层数据的2倍。     

蓝光光盘产品今春亮相

由日欧韩三国共 9家 AV产品制造商结盟的“Blu- ray Disc Founders(蓝光光盘组织 )”将从今日开始提供新一代光盘规格“蓝光光盘”的技术授权。此次的授权对象是用于录像机的可擦写光盘规格。此次的合同不包括蓝光光盘规格的相关专利授权 (版权保护技术除外 )。相关专利授权必须单独与各企业签定合同。此次授权的开始使得投产蓝光光盘录像机的环境得以完备。在蓝光光盘录像机的开发中居于领先地位的索尼公司 ,在展会等场合已经展示了完成度非常高的录像机试制品。 2 0 0 2年 12月索尼就称该机心脏元件的 Ga N系蓝紫色半导体激光器与日亚…     

模块化蓝光光存储性能静态测试系统

蓝光光存储是信息存储领域发展的一个重要方向。测试系统是研究蓝光光存储材料的必备条件，为建立蓝光光存储研究平台，设计和搭建了一套模块化蓝光光存储性能静态测试系统。激光工作波长为406．7nm。系统采用调制解调技术降低系统噪声，提高测量粘度：采用光点移动模式降低对样品尺寸的要求；采用纳米平台提高记录点的反复定位性能。实验结果证明测试系统性能良好，可以满足蓝光光存储性能静态测试要求。     

一种超大容量自动光盘库的设计与实现

当前蓝光光盘的寿命已超过50年,光存储的可靠性远高于硬盘,寿命也远长于磁带,但单盘容量较小、存取性能较低的缺点限制了光盘在大规模归档系统中的应用。提出了一种新型超大容量机械手自动换盘的光盘库系统,该系统能够在标准尺寸的机柜中容纳12 000张蓝光光盘,数十个光驱可并行读写,对外的吞吐率达到1 GB/s。除了高度并行之外,还使用了磁光电融合结构和虚拟化存储机制,通过磁电作为光存储的大容量缓存,提高存取性能,将大量的光盘存储空间虚拟成单个文件卷存储池。该系统的光盘调度、刻录和读取完全实现自动化,并提供给用户通用文件访问接口。综合这些技术,既发挥了光存储介质的大容量、长寿命、低成本、低能耗的优点,又克服了光存储系统速度慢、性能低的缺点,同时提供了用户友好的使用界面和环境,实现了与现有信息系统的无缝对接。     

中国蓝光高清普及大潮即将来临

随着索尼、松下、飞利浦等代表厂商纷纷推出新一代价格更低的蓝光播放机,蓝光在国内市场开始步入迅速发展的良性轨道。众所周知,蓝光（Blu-ray）亦称蓝光光盘（Blu-ray Disc）,通用缩写为BD,以高分辨率画质与高信息量的声效见长,2008年2月打败HDDVD格式之后,蓝光光盘正式成为继DVD之后的下一代光存储格式。     

Sony蓝光高清与极速刻录齐上阵

索尼公司近日面向全球推出全系列蓝光存储产品,标志蓝光产品正式进入市场。索尼宣布在中国市场推出BWU-100A(蓝光)、AW-G170A、DRX-830UL、DRX-S50U4款全新的光存储产品,全部产品均符合RoHS环保要求。BWU-100A:蓝光驾御完美应用BWU-100A是索尼在国内首次对外正式发布的蓝光光存     

Write Strategy Learning for Optical Dye Recording

Write strategy tuning for optical recording devices (ORDs) is laborious and time consuming. An automated learning approach based on the genetic algorithm (GA) is proposed to automatically learn the write strategy implemented in an ORD for dye recording media. To evaluate the writing performance associated with every set of writing parameters in the write strategy, jitters corresponding to different lengths of pits and lands are utilized as the optimization index. A system is designed that integrates the jitter measurements with the GA based write strategy optimization. To optimize the writing parameters in write strategy, all the parameters are implemented as genes in GA's chromosome and the jitters are transmitted from the ORD to a PC through the integrated drive electronics bus. It will be shown that the proposed automated learning approach can successfully learn the write strategy for different dye recording optical discs at different recording speeds.     

Coded modulation and precoding for electron-trapping opticalmemories

This paper develops coding and signal processing approaches for a novel optical recording channel that arises from electron-trapping phosphor materials. The recording medium allows multiple reads and writes, and one important feature is that the read process serves to erase the disk. This feature would enable vendors of prerecorded video to provide customers with one-time services. For applications where this feature is not desirable, the data can be immediately rewritten. From a communications viewpoint, the most important feature of this new channel is that, subject to a peak constraint, it supports a continuum of recording levels. The combination of read and write processes creates a partial-response channel, and the ability to write a continuum of levels makes it possible to employ precoding techniques, such as the one developed by Tomlinson (1971) and by Miyakawa and Harashima (1969). This is fundamentally different from magnetic data storage, where the read/write process creates a partial-response channel but where it is only possible to write two levels at the input to that channel. This paper shows that the use of precoding and coset codes can significantly improve upon the recording densities (and recording rates) that can be achieved by using M-ary run length constrained codes to eliminate intersymbol interference (ISI) at the output of the read/write process. The approach presented is applicable to any optical recording channel that supports a continuum of recording levels     

基于光致变色原理的多阶存储实验研究

多阶存储是一种无需减小记录波长或增大数值孔径而显著提高光存储容量的新颖方法。对光致变色材料采用不同的光能量写人，读出时则具有不同的吸收率，该特性可用来实现多阶数据存储。在研究光致变色材料曝光特性的基础上，提出了基于光致变色原理的多阶存储数学模型，该模型反映了光致变色材料吸收率与曝光量之间的非线性关系，为光致变色材料的多阶存储写策略的优化提供了理论依据。在4阶和8阶静态存储实验结果中，各信号峰值之间有明显的阶次变化，且信号之间没有交叠现象，从而验证了利用该材料进行多阶存储的可行性。将该多阶技术应用在实际光盘存储中，可实现两至三倍于普通光盘容量的高密度存储。     

Mechanisms for High‐Performance and Non‐Local Photoisomerization Gratings in a Sol–Gel Material

Novel azo‐containing sol–gel films exhibiting outstanding properties for optical applications via nonlocal photoisomerization gratings were reported recently, although the underlying mechanisms were not well understood, especially regarding the unexpected non‐local effect. Here, this photoisomerizable sol–gel material is characterized in‐depth, analyzing the design and fabrication strategy, and discussing the aspects that enable the efficient photoresponse, with focus on the holographic recording. The material consists of an azochromophore‐rich silica matrix containing glycidoxypropyl groups, which provide increased flexibility and internal free volume for improved dye photoresponse. The matrix characteristics allow a novel procedure for fabrication of thick optical films, in which chromophore aggregation is ruptured by thermal annealing while keeping the material centrosymmetry (beneficial for high hologram contrast). The molecular photo‐orientation promotes alignment of microscopic domains in a cooperative motion, not reported previously in sol–gel materials. This collective mechanism enhances the material response and explains some intriguing features of photoisomerization gratings. In particular, there is evidence that spatially shifted domains are related to the grating nonlocal nature. Different recording (write–erase–write) procedures that distinctly affect the photoalignment at both molecular and microscopic level are studied. The holographic performance drastically changes, which can be selectively exploited for either long‐term or dynamic holography.     

大克尔角磁光材料测试系统试验研究

磁光存储系统中,存储信息的介质——磁光材料膜的读/写性能直接影响了系统信噪比和信号质量,直接擦写等性能指标,因此,研制和开发高性能磁光材料是改善系统性能的直接手段.本文介绍了一个磁光材料读/写性能测试系统以及利用该装置对大克尔角磁光材料MnBiAl样品进行的静态读/写试验,测试结果可以为分析和改进这种新型磁光材料的读/写性能及其实用性提供有益的数据.     

Electrically amplified optical recording

We describe a new optical recording geometry which reduces the laser power required to record micrometer size spots to 0.1 mW in the power limited regime. This is achieved by shifting the power burden from the laser to a voltage source which is connected across a thin-film transparent conductor-photoconductor-conductor sandwich. The sharply focused laser beam switches the photoconductor to a low resistance, and this greatly increases the electrical power dissipated in the illuminated spot. The result is an ablation of the films, leaving a pit with high optical contrast. By turning off the voltage, the record can be read with the same laser power that was used to write.     

相变光盘的多层膜结构

实用的相变光盘膜应由包含相变介质膜和匹配膜的多层膜结构绍成。本文根据膜系特征导纳矩阵,匹配设计了相变光盘的多层膜结构。设计结果表明:(1)λ=8300 处多层膜结构较单层膜结构(只有相变记录介质膜)对写入激光吸收提高一倍左右;(2)反射率对比度有较大提高,R_c∶R_a可达4∶1。最后对设计结果给出了实验证实。     

Three-dimensional optical data storage through multi-photon confocal microscopy and imaging

Three dimensional optical data storage is one of the most promising tools to respond to the always growing demand for high data storage capacity. Here, we focused a femtosecond laser source by means of a confocal microscope onto different transparent recording media. The purpose of the study is to probe the capability of the system to independently address different data layers within the storage medium achieving thus three dimensional data storage. We demonstrated the possibility to write superposed independent layers of data due to either multiphoton excitation or to local optical breakdown and the performances observed in the different types of media used are compared.     

基于微球透镜远场超分辨率成像方法研究

在可见光波段,传统光学显微镜的成像分辨率被限制到200nm。为了突破衍射极限,采用了将微球与传统光学显微镜相结合的方法来获得远场超分辨率成像。首先通过理论分析平行光通过微纳结构物体后物光波在空气中的传输,进而分析微球将倏逝波转换成传输波实现远场超分辨的成像机理;其次通过仿真研究了微球的光纳米喷射特性,可知微球光纳米喷射的半径尺寸小于入射光波长的一半;最后搭建了基于微球与传统光学显微镜相结合的超分辨率成像实验系统。结果表明,将蓝光光盘作为被测物体,通过该成像系统可获得100nm的远场超分辨率成像; 该成像系统可以对微纳元件结构进行检测。这一结果对光刻技术、生物医学等领域是有帮助的。