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We developed a system to measure disk noise as a function of both radial and angular position. In order to obtain an accurate disk noise measurement, crosstalk and intersymbol interference were avoided by recording regularly repeating pit patterns and the influence of electronic and laser noise was removed by averaging techniques. We found the system’s mapping ability and its high sensitivity to be very useful in investigating disk noise phenomena in the mastering process. We used the system to assess the accuracy and reproducibility of the photopolymerization replication and Al vapor deposition processes. Also, we investigated the choice of photoresist and found that photoresists with the combination of the narrowest molecular weight distribution and the highest photo-active compound content resulted in the lowest disk noise levels. Our system can, in principle, be adapted to evaluate magneto-optical and phase change disks. 相似文献
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不同于传统的非制冷红外成像技术,提出了基于微电子机械系统(MEMS)的新概念光学读出非制冷红外成像技术。它的光学读出系统基于空间刀口滤波原理,具有高灵敏度、高分辨率和高抗震性等优点,但同时也受到了反光板的弯曲变形、粗糙度等复杂因素的影响。在大量实验数据的基础上,利用夫琅禾费近场衍射理论,建立了复杂因素下光学灵敏度的理论分析模型,详细分析了刀口滤波位置、反光板的长度、曲率半径、粗糙度、LED光源的强度以及扩展宽度等对光学灵敏度的影响,并提出了通过极限操作使系统的光学灵敏度最大化的光学优化方法。 相似文献
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WANG Yang GU Donghong GAN Fuxi 《Chinese Journal of Lasers》2001,10(3):206-210
1 Introduction Recentlyopticaldisksabletostorealargequantityofinformationhavebeenusedascompactdisk (CD ) ,digitalversatiledisk(DVD) ,andtheirrecordableorrewritabletypes(suchasCD R ,CD RW ,DVD R ,andDVD RAM ) [1 ] .Anopticaldiskisakindofmultilayersystemdepositedona… 相似文献
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The signal-to-noise ratio (SNR) in the photochromic super-resolution readout of optical disks was theoretically analyzed. The shot noise limited SNR, such as that in magnetooptical disks, was improved only for the short recorded mark. However, the media noise limited SNR, such as that in phase change disks, was greatly improved for both short and long recorded marks. 相似文献
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Theoretical Analysis of Super-Resolution Optical Disk Mastering Using a Photoreactive Dye Mask Layer
The super-resolution mastering of read-only optical disks using a photoreactive bleachable dye mask layer was theoretically analyzed. Equations have been derived which describe the photoreactions of the resist layer and mask layer. A numerical simulation based on these equations showed that the transmittance of the mask directly affects the quality of the formed pit shape. A high-quality pit shape is obtained by using a low transmittance mask. 相似文献
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信息读出光学系统是波导多层存储方法的重要组成部分,从几何光学角度,提出了两种信息读出光学系统的理论设计,并对两种系统的特点进行了实验研究,结果表明两种光学系统都是可行的,而且对波导多层光存储的进一步研究及实用化都有一定的参考价值。 相似文献
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1.IntroductionLaserdiodehasbeenx`idelyusedinfibrc-opticcommunicat:onandopticaldisk$yctems.LaserbeamIsradiationangle(fullangu1aratha1f-maximumintensitypoint)ismeasuredbothparllelandPerpendiculartothcjunctionp1anclgenera1ly.o//=6,~1o",oJ-=2o"~5O':Inerasableopticaldisksystemsasmagneto-optica1disksystems,thelaserbcamiscollimatedandshapedtobecircularsymInetricbeaminordcrtoaquireahighintensityandhighqualityscanningbeamiPot,butitsoptica1systemiscomplicatedandeasyaddingassocialaberration.usingaellip… 相似文献
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An erasable optical disk system requires an objective lens having minimum chromatic aberration. We estimated the chromatic aberration of a conventional refractive singlet. At shorter wavelengths, the focus shift of an objective lens exceeds its depth of focus. A diffractive-refractive hybrid lens can compensate chromatic aberration perfectly. Diffraction efficiency, however, decreases with the degree of compensation. We simulated the relationship between chromatic aberration and diffraction efficiency. Fabrication of designed lenses by glass molding was achieved, and the results showed excellent agreement with the simulation. 相似文献
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为了使光盘获得优良的记录/读出性能并能够长期稳定地使用,必须优化设计相变光盘的多层膜结构。采用自行设计的模拟分析相变光盘读出过程设计软件,从光学角度出发模拟计算了蓝光(405nm)相变光盘的膜层结构,研究了多层膜系的反射率和反射率对比度等光学参量与各层膜厚度和槽深的关系。研究得出的最佳多层膜结构为:下介电层/记录层/上介电层/反射层的厚度对于台记录为100nm/10nm/25nm,/60nm,而对于槽记录则为140nm/15nm/30nm,/60nm,槽深为50nm。模拟计算结果对于将来高密度蓝光相变光盘的制备具有一定的指导意义。 相似文献
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We propose a novel signal processing technique by which we can increase the effective signal to noise ratio of optical discs. This technique is capable of reducing the influence of random noise even when the playback signal contains a distortion. We apply this signal processing technique to single carrier independent pit edge recording optical disc system. When a linear recording density of 0.2 μm/bit and a track pitch of 0.8 μm for an optical pickup is used in a DVD pickup (γ =635 nm, NA=0.6), the experimental results show that the system can obtain tangential and radial skew margins of ±0.5° and ±0.75°, respectively. From the experimental results, we estimate that the proposed method is capable of increasing the capacity of DVD by a factor of about 1.2. 相似文献
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从理论与实验两方面分析了光网络节点设备光信噪比(OSNR)恶化量的测量,导出了单节点设备输出,输入侧光信噪比之差的公式。理论分析表明:节点设备输出,输入侧光信噪比之差值在一般测试条件下不能反映节点设备对光信号的影响,能作为节点设备光信噪比的恶化量来衡量设备对光信号的影响;为使测量结果能反映光节点参数对光信号的综合影响,测试系统应当满足文中给出的增益条件C=1。实验结果支持了理论分析,实验结果表明,对于C=1时光信噪比恶化量为4.5dB的光点设备,当C从3变化与0.16时,其输入、输出侧光信噪比之差从1.8dB变化到11.3dB. 相似文献
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利用光致变色材料的灰度分阶特性可以实现多阶光存储。以傅里叶光学和光致变色记录符的可叠加性为基础,采用霍普金斯标量衍射理论的经典归-化坐标,对光致变色多阶光存储中的光学串扰进行了理论建模和数值分析。作为后续电通道补偿设计的前提。数值计算结果表明:相邻记录符与盘基信号的交叉串扰项是光学串扰的主要成分,且随着中心距的增加,相邻记录符引起的串扰迅速降低;当无寻道误差时,邻道记录符引起的串扰可以忽略;高阶记录符引起串扰要明显高于低阶的串扰。且影响多阶存储的可分阶性;实验结果很好地验证了所建立的模型的合理性。 相似文献
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DSP图像处理技术在空间瞬态光辐射定位探测中的应用 总被引:3,自引:4,他引:3
在分析空间瞬态光辐射信号成像特点的基础上,提出了一种在空间瞬态光辐射信号定位系统中,用高速浮点DSP芯片实现图像处理的方案.图像处理过程为:首先通过阈值分割滤除背景和弱噪音;然后根据目标信号的时空连续性进行目标识别以去除强噪音;最后对识别出的目标像点进行重心位置的提取.实验表明,该硬件图像处理方案具有高的实时处理性和定位准确性,可以很好的满足系统要求. 相似文献
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考虑到抽运损耗、走离、色散和非线性等效应,用分步傅里叶方法求解耦合的非线性薛定谔方程组,就强脉冲信号在连续光抽运光纤参变放大器中的放大情况进行了理论研究。研究结果表明,强脉冲信号除经历振幅放大,脉冲时域展宽等过程外,还会发生令人感兴趣的脉冲分裂现象,即一个脉冲信号分裂为两个子脉冲。而且即使在连续光抽运的情况下,走离效应对强脉冲信号的放大也产生了显著影响,即促使两个子脉冲振幅不等以及脉冲漂移。最后,强脉冲信号独特的放大特性用光纤参变放大器的饱和增益特性做了很好的解释,并指出脉冲分裂现象在信号抽样、脉冲压缩、光时分复用系统中有潜在用途。 相似文献