磁光记录新材料

介绍了磁光记录的物理原理和最新技术。非晶态稀土-过渡金属合金膜的发现加速了磁光记录的发展，在高密度多层膜记录中，由于他的宽温热磁特性，他记录的热磁斑直径仅数十纳米。为读出这么小的斑点，还必须加快发展更新的读出技术。     

磁光存储多层膜系统的光学与热分析方法

采用光学转移矩阵法计算激光照射下磁光存储多层膜的磁光及光学响应，光强分布及焦耳热损失分布，再用有限元方法求解在这种多层膜中的热传导方程，从而得到激光照射下多层膜系统中的温度场分布，这种方法可用于磁光光盘的光学与热学设计。     

相位延迟对磁光盘静态检测影响的研究

本文运用琼斯矩阵分析了相位延迟对磁光盘读出特性的影响,分析表明,相位延迟导致磁光盘读出信号下降;采用复合补偿法可克服相位延迟,提高磁光有效信号读出。     

具有磁放大层的高密度磁光盘

具有磁放大层的高密度磁光盘张绍高通常，光盘记录密度的极限取决于记录激光的波长。读出时，如果记录小坑的尺寸小于拾取激光光点的直径时，在激光光点中将会有多于一个以上的小坑，以至使重放信号产生干涉，导致信息读出困难。对于磁光盘，以前也研究出了不受激光波长限...     

磁光记录技术

80年代崛起的光储存技术,无疑是科学技术的一大飞跃。它的代表是ＣＤ（ＣｏｍＰａｃｋＤｉｓｋ）技术,它具有许多优良特性：体积小、保存环境要求低、记录密度高、非接触性读出无磨损和能快速非线性重放。现在已成为社会工作、社交、文化教育、各种信息咨询等活动中不可缺少的重要媒体。然而,ＣＤ是只读光盘存储系统,不能满足目前信息时代的大容量信息的存储、交流的要求。而磁光存储系统在可擦写光盘存储领域极具发展前途,汇聚了光储存和磁储存的优点。它记录密度高、储存容量大、可靠性好、价格低,特别是具有可擦写、携带和交流极其…     

Bi代石榴石磁光膜／金属反射层／玻璃多层结构磁光盘的优化设计

从磁光读出和热磁写入两者结合的角度提出一个新的优化目标函数．并用其完成了Ｂｉ代ＤｙＧａＩＧ／金属反射层／玻璃多层结构磁光盘的优化设计。结果表明新优化目标函数更具实际意义。     

磁光记录磁畴及其热稳定性研究

磁光存储的原理是热磁记录，信息以磁畴的形式存储于记录介质中。磁畴的形貌及其热稳定性对磁光盘的存储性能有很大影响。报道了ＴｂＦｅＣｏ磁光盘磁畴形貌及其热稳定性的实验研究结果。     

宽温环境下磁光盘写入光功率的优化

利用有限单元法研究了环境温度、写入光功率、磁光盘膜面温度分布三者间的关系，在此基础上导出了宽温环境下的最优写入条件，该条件为优化宽温磁光盘读出性能提供了依据。     

宽温环境下磁光盘瞬态温度场的研究

本文利用有限单元法,在宽温环境(-20℃～+88℃)下,对层状膜结构磁光盘的瞬态温度场进行了模拟,着重分析了环境温度对磁光盘温度场的影响,研究了不同环境温度下磁光盘记录灵敏度同记录光脉冲宽度的关系,为进一步研究宽温环境下磁光盘的热磁记录和磁光读出特性提供了分析手段。     

稀土—过渡族金属非晶态磁光材料信号读出特性研究

在计算RE-TM饱和磁化强度和温度关系曲线的基础上,本文建立了一种适用于计算磁光光盘读出信号质量与读出激光功率关系的方法,对经优化的四层膜结构实例给出了最佳读出激光功率,并讨论了稀土含量变化时,对最佳读出激光功率和信噪比的影响,结果与有关的实验规律相吻合。     

Diode laser optical recording using trilayer structures

A new high-power diode laser and a more sensitive trilayer disk structure useful for FM video and digital data recording have been demonstrated. The diode laser is a constricted double-heterojunction large optical cavity (CDH-LOC) device capable of up to 100 mW output power in a single stable mode. By improving the thermal efficiency of the trilayer structure, the sensitivity is improved by a factor of two over previously reported trilayer structures. Digital signals with data rates up to 30 Mbits/s and storage capacity in excess of3 times 10^{10}bits are demonstrated using a plastic 12 in diameter disk rotating at 30 r/s while digital systems with data rates up to 60 Mbits/s and storage capacity in excess of 10¹¹bits are shown to be feasible.     

Full Color 3-D Imaging by Digital Holography and Removal of Chromatic Aberrations

In color digital holography the recording and reconstruction of three holograms, by an optical setup operating in multi-wavelength mode, is necessary. Incorrect superposition of different images at various wavelengths may occur due to the presence of chromatic aberrations. We demonstrate that the compensation of the chromatic aberrations can be achieved by using all of the information contained in the multi-wavelength digital holograms. Chromatic aberration is extracted from phase maps reconstructed at different wavelengths, resulting in perfect full color amplitude reconstructions. The method has important applications in color 3-D holographic imaging and display.     

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。     

A rotary encoder based on magneto-optical storage

A new kind of the rotary encoder based on the magneto-optical (MO) storage is proposed. Using the MO methods, a small high-precision high-response rotary encoder can be realized. High precision is achieved by a two-stage process in which the code disk is firstly written using the direct transfer recording, and then rewritten using the corrections based on the measured errors. The systems for writing to, reading from, and evaluating the MO encoder are developed, with the optimal MO encoder reading and writing parameters determined experimentally. A trial MO encoder with a resolution of 9000 pulses/revolutions is created directly from a reference encoder, delivering an accuracy of approximately 2.8 in. The maximum resolution and response frequencies achieved are 18000 p/r and 400 kHz. After the corrected transfer recording, accuracies of 1.3 in at a resolution of 2250 p/r and 1.7 in at 9000 p/r are achieved.     

Magnetooptics: A thermomagnetic recording technology

Erasable magnetooptic (MO) recording is viewed as a possible successor to electromagnetic recording that is used today in high-performance disk drives for mainframe computers, hard disks, and floppy disks for personal computers and magnetic tape drives. A large number of rare earth-transition metal alloys have been investigated for use as the magnetic recording material. The properties of the films are very sensitive to the film deposition processing parameters. Accelerated life tests show that there are magnetooptic materials that do have all of the necessary properties and stability for use in computer digital storage.     

光纤耦合波长复用的全息光盘存储记录

详细描述了用光纤耦合、波长复用的全息光盘仔储光路．指出在全息光盘驱动器即将市场化的今天．由于其光路简单、光学元件较少、性价比高．很有可能成为新的全息光盘驱动器的核心技术之一。由于短波长单模光纤及其双波长光纤分束器件的要求比较高．而用多模光纤进行准单模输出调整．以及用分光棱镜进行光束的分光．同时用对双波长敏感的光致聚合物材料进行存储．其光谱灵敏度均匀．光谱范围互不重叠。实验结果表明．光路结构合理．存储效果良好。     

Space-time processing with photorefractive volume holography

Photorefractive volume holography for processing ultrashort optical pulses carrying spatial, temporal, and spatiotemporal optical information is introduced. These new holographic methods can process temporal information, i.e., the temporal evolution of optical pulse signals, in addition to the usual spatial information. Photorefractive volume holographic materials provide the medium necessary for recording and reconstruction of such optical information in real time. Spatial and temporal holography with photorefractive volume holographic materials are introduced, compared, and discussed. The direct time-domain holography is shown to possess two disadvantages, low fringe contrast and limited recording time, which is overcome by using the method of spectral domain holography. Applications of direct time-domain and spectral-domain holography for image processing, temporal matched filtering, optical pulse shaping, three-dimensional (3-D) optical storage, and optical interconnects are discussed. Furthermore, the combined space-time holographic processing that allows the conversion between the spatial and the temporal optical information carrying channels is introduced. This method is used to demonstrate experimentally parallel-to-serial and serial-to-parallel data conversion for one-dimensional (1-D) images and image-format data transmission. The demonstrated holographic processors provide the advantages of self-referenced signal transmission and self-compensation for optical dispersion induced by the holographic materials, communication channel, as well as other optical components     

多层结构磁光记录介质的优化设计和制备

本文提出了一种计算磁光多层结构光学特性的新方法,它可以用来计算包含有一层或多层磁性薄膜的磁光多层结构的反射率、Kerr角及椭圆度等光学特性,并得到了应用.