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.     

Approximated Vector Diffraction Theory for Readout Signal of Multi-Level Run-Length-Limited Discs

Multi-level run-length-limited read-only optical storage is a kind of high density storage method. The width and height of recording marks are varied with different levels, which is the key technology for the optical storage. Then the readout signal of these discs with complex recording marks is computed by vector analysis method, it is very hard and time-consuming. Approximated vector computation combines the convenience of scalar method and precision of vector method, which is effective for multi-level run-length-limited read-only optical storage.     

Multilevel optical data recording methods on phase-change media

Multilevel data storage (ML) is a new method in the optical storage field, which is also a trend for improving the capability of future optical discs. This article introduces several ML methods based on phase-change media including pit depth modulation (PDM) and mark radial width modulation (MRWM). In addition, some disadvantages and advantages concerning the principle of these methods will be discussed. Finally, a new ML method will be advanced, through which the levels in one recording pit will be increased evidently.     

Experiments of Multi-Level Read-Only Recording Using Readout Signal Wave-Shape Modulation

An innovative multilevel read-only recording method is proposed. In this method, a short pit/land is deliberately inserted to the original land/pit. This modifies the wave-shape of readout signM. Taking the wave-shape as the symbol of level detection, a signal wave-shape modulation （SWSM） multilevel method is realized. This method is carried out and validated on the DVD read-only manufacture and readout system. A capacity of 15 GB can be expected, and a bit error rate of 10-4 is achieved. The capacity can meet the demand of high definition movie publication. This method also provides a potential multi-level solution for other storage formats and systems.     

Formation of blazed holographic gratings

Various methods for the recording of blazed holographic diffraction gratings are presented and the regions in the wavelength-groove density plane for which they can be used are shown. The gratings are made in the positive photoresist Shipley AZ-1350. The diffraction efficiency for s and p polarization was measured as a function of wavelength and angle of incidence. An absolute efficiency of 80% was achieved.     

模压全息图母版的拍摄研究

目前拍摄模压全息母版用的记录材料都是光刻胶.本文从它本身的特点(灵敏度低,浮雕型相位光栅和拍摄对象是散射物体等)出发,指出要拍摄出质量好的光刻胶母版应当注意到的问题.诸如拍摄参数的选择应同时考虑到衍射效率和信噪比、照明的均匀性问题、逆共轭光再现、消偏振、相干长度、外界振动对拍摄的影响问题.通过分析表明高质量的全息图不可能靠延长曝光时间来获得,使用相干性好的大功率激光束来拍摄,是非常有必要的.     

Quantum lithography beyond the diffraction limit via Rabi oscillations

We propose a quantum optical method to do the subwavelength lithography. Our method is similar to the traditional lithography but adding a critical step before dissociating the chemical bound of the photoresist. The subwavelength pattern is achieved by inducing the multi-Rabi oscillation between the two atomic levels. The proposed method does not require multiphoton absorption and the entanglement of photons. It is expected to be realizable using current technology.     

一种大F数微透镜阵列的制备方法

针对大F数(大于10)微透镜阵列难以制备的现状,提出了一种制备大F数微透镜阵列的方法.首先采用传统光刻胶热熔法及刻蚀技术制作出成形的微透镜阵列,再将一层具有较高粘滞系数的光刻胶均匀地涂覆在该微透镜阵列上,在光刻胶的粘滞作用以及烘烤过程中光刻胶自身表面张力的共同作用下,微透镜阵列的F数得到提高.采用该方法制备的二氧化硅微透镜阵列的F数达40,与传统大F数微透镜阵列的加工方法相比,该方法简便易行、制备的微透镜阵列面形良好,且只需调节光刻胶的粘滞系数,即可获得F数不同的微透镜阵列.     

模压全息图的颜色设计及其记录方法

目前模压全息广泛地应用于商品标识、卡通、贺卡等，如何制作出色彩鲜艳、亮度高、清晰的模压全息图是至关重要的。本文从两束光干涉的简单模式讨论模压全息图的颜色设计，给出几种实用的和可能用的浮雕全息图的记录方法，并介绍常用光致抗蚀剂记录材料的特性及其处理工艺。     

Thin film optical components duplication method

A method which permits duplication of thin film optical components is described. A metallic master fabricated from an original recording on photoresist, is used to make numerous copies by embossing a sheet of a non-expensive plastic material. Some examples are given to illustrate the method.     

凹球面涂布光刻胶均匀性研究

通过对离心法在凹球面上涂布光刻胶过程进行分析,阐明了离心状态下光刻胶在凹球面基底上的流动机理,结合试验提出影响凹球面涂布光刻胶膜厚均匀性的主要因素有胶液粘度、旋涂速度、旋涂时间,列举了以上因素引起的各种现象,并进行了理论分析。引用凹球面旋涂光刻胶的膜厚公式,建立了膜厚与速度关系数学模型;利用流体力学原理解释了有限圆形空间中流体速度对膜层均匀性的影响,从而解决了大曲率凹球面上制备微细图形结构的关键工艺问题,对非球面上制备微细图形具有借鉴作用。     

红外微透镜阵列及其与MCT红外焦平面的集成

针对中短波碲镉汞（MCT）红外焦平面探测器的使用要求,设计了用于混合集成和单片集成且尺寸大小与探测器像元结构匹配的方形底折射微透镜阵列。采用热熔成形和（反应）离子柬刻蚀转移技术制作了多种红外材料微透镜,如Si、Ge、GaAs、蓝宝石以及红外玻璃（IRG-103和IRG-104）微透镜。针对混合集成和单片集成的不同要求,选用多种光刻胶如AZ6112和AZ6130等不同厚度的胶以及SUN-120P低熔点正型光刻胶,进行热熔和刻蚀实验,遴选分别适用于混合和单片集成的光刻胶。优化光刻胶和衬底材料的刻蚀速率比,得到高填充因子和合适光学参数的微透镜阵列。探究了SUN-120P低熔点正型光刻胶的特性和通过离子柬刻蚀转移视线实现零间距透镜的工艺。最后介绍了与MCT红外焦平面阵列器件的集成方式和工艺进展。     

Bi置换DyIG溅射薄膜的磁光性能与干涉效应的研究

本文报道用高频溅射法在玻璃衬底上制备的Bi置换DylG薄膜具有高的矫顽力和矩形比。在500nm波长附近,法拉第旋转角达7.5°/μm。经热磁记录的磁畴稳定。并发现薄膜表面蒸镀不同金属时,随不同波长和磁光层厚度干涉效应有较大差异。利用此特性可对石榴石记录盘片进行最佳性能设计。 关键词：     

Etching blazed grating into quartz substrate with selectivity 1:1 against photoresist by inductively coupled plasma technology

Inductively coupled plasma (ICP) etching technology is becoming widely used in the fabrication of micro-optical elements. Because of its advantages such as relatively high etching rate and anisotropic etching, ICP technology is receiving more attention. Selectivity 1:1 of the substrate against photoresist is very convenient, because we can easily get the same structures which were designed on the photoresist. Through extensive experiments we have achieved an optimized etching condition under which the transfer process generates fairly smooth etched structures with selectivity 1:1. The first order diffraction efficiency of the etched blazed gratings is 83.5% which is a little bit lower than the theoretical efficiency 88.9%. The diffraction of etched blazed gratings matches the theoretical results well.     

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     

激光光刻中的超分辨现象研究

激光光刻是加工微光学及二元光学掩模的主要手段。光刻的最细线宽对所加工的二元微器件性能起决定作用。本文导出了会聚的高斯光束用于激光光刻时在光刻胶内的光场近似上此可判断出能光刻线条的分辨力。若入射高斯光束受到振中相位调制时,胶层内的光强分布将发生变化,从而影响曝光线条的线宽和质量。计算看出：当入射光中心环受到遮拦时,可以得到超光刻物镜极限分辨的线条宽度（０．６μｍ）,但此时对曝光能量控制要求很高。在激     

Pixel-based partially coherent image method for maskless lithography system

Maskless lithography (ML) provides a fast and low-cost method for projecting the images of IC or micro features onto photoresist. However, it needs an efficient simulation method to evaluate the performance of lithography process. In this paper, a pixel-based partially coherent image method for digital micro-mirror device (DMD) based ML is proposed based on the linear invariant theory. In our method, the mask is sampled by DMD pixel (each pixel corresponding to each micro-mirror) and expressed by rect function. Using the shift theory of Fourier transform and the stacked pupil operator approach, we build a matrix Φ for system response function of rect function. If the DMD pixel state matrix is S, then the aerial image can be calculated with two matrix multiplication I(x,y) = SΦ.     

Threshold Property of Photoresist Film for Two-photon Optical Memory

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Latency optimization for Federated Learning over Wireless Power Transfer

Federal Learning (FL) is an emerging technology in the field of machine learning (ML). Compared with traditional ML, FL is an attractive method to deal with data security issues of the user-side. So that FL can realizes its full potential in terms of low latency and high energy efficiency (EE), this paper introduces a new framework: In the wireless communication network scenario, we propose an FL architecture based on Wireless Power Transfer (WPT). By combining WPT technology and FL, we can realize green wireless communication under the premise of ensuring user privacy. We formulate a joint calculation and communication optimization problem to optimize the latency of local calculation, uplink and downlink transmission without consuming user-side energy. The problem formulas listed according to the optimization problem are non-convex. They are first transformed into convex form, and then a low-complexity iterative algorithm is used to solve them optimally. Simulations show that our proposed FL method design has achieved a significant performance improvement over other benchmark tests.     

Threshold Property of Photoresist Film for Two-photon Optical Memory

Two-photon threshold property of photoresist films have been studied by changing exposure energy. When photoresist film is irradiated by Ti∶Sapphire laser with wavelength 770 nm, pulse width 130 fs, repetition rate 82 MHz, the damage and recording thresholds of the material are 9.15×105 J/cm2 and below 5.57×105 J/cm2, respectively. The principle experiments of two-photon optical memory are demonstrated in photoresist film. The patterns of optical bit data storage are realized at different input power density. The corresponding 3-D tomographies of these recorded spots are scanned under near-field optical microscope.