Si掺杂Ag基超分辨薄膜读出性能研究

超分辨薄膜是一种能够实现突破光学衍射极限的功能薄膜,它在超分辨近场光存储技术中起到至关重要的作用。采用磁控溅射共溅的方式制备了Ag掺杂一定量Si的超分辨复合薄膜,测试了其作为掩膜层的超分辨光盘读出性能,并获得了最佳的薄膜制备条件,即当Ag溅射功率为55 W,Si为95 W,溅射时间为80s,薄膜厚度为39nm时,超分辨光盘的读出信号载噪比(CNR)最高为28dB。用X射线光电子能谱测量了上述薄膜的组成,用扫描电子显微镜观察了薄膜微区形貌,并用椭圆偏振光谱仪测量了薄膜的光学常数和厚度。超分辨复合薄膜的读出机理可以用Ag的散射型机理解释。光盘在持续读出10万次以后读出信号基本没有下降。     

超分辨技术在光盘中的应用研究

超分辨技术是一种无需用减小波长或增大数值孔径的方法减小记录点尺寸而能读出超过衍射极限信号从而有效增加存储密度的一种方法，超分辨可以通过调整光学系统或者调整光盘的结构来实现，在超分辨光盘中，超分辨是基于掩膜的光学性质随入射激光强度的非线性变化而实现的，在磁光盘中第一次引入超分辨技术后，超分辨技术的应用有了很大发展，在目前是提高光盘存储密度的有效方法，在各类光盘中都有良好的应用，近场超分辨技术的出现使相变光盘的超高密度记录和读出成为可能，文章综述了超分辨光盘的发展现状和发展方向。     

超分辨技术在光盘中的应用研究

超分辨技术是一种无需用减小波长或增大数值孔径的方法减小记录点尺寸而能读出超过衍射极限信号从而有效增加存储密度的一种方法.超分辨可以通过调整光学系统或者调整光盘的结构来实现.在超分辨光盘中,超分辨是基于掩膜的光学性质随入射激光强度的非线性变化而实现的.在磁光盘中第一次引入超分辨技术后,超分辨技术的应用有了很大发展,在目前是提高光盘存储密度的有效方法,在各类光盘中都有良好的应用.近场超分辨技术的出现使相变光盘的超高密度记录和读出成为可能.文章综述了超分辨光盘的发展现状和发展方向.     

菌紫质高密度偏振全息光数据存储实验研究

实验研究了基因改性菌紫质BR_D96N薄膜在不同偏振光记录下的全息存储特性，比较了不同 偏振态记录光和读出光对衍射像光强及信噪比的影响. 实验结果表明，与其他偏振全息记录 相比，正交圆偏振光记录可实现衍射光偏振状态与散射噪声偏振状态的分离，得到高信噪比 的衍射像，同时还具有高的衍射效率. 以 He_Ne 激光器（633nm，3mW）为记录和读出光源 ，用空间光调制器作为数据输入元件，CCD作为数据读出器件，采用傅里叶变换全息记录的 方法，在 BR_D96N 薄膜样品60μm×42μm的面积上进行了正交圆偏振全息数据存储，达到 了2×10⁸bit/cm²的存储面密度，并实现了编码数据的无误读出与 还原. 关键词： 菌紫质 偏振全息 光致变色 光致各向异性 高密度光存储     

YBCO超导薄膜中磁通宏观量子蠕动现象的研究

我们对低温下YBCO（123）超导薄膜样品中磁通的宏观量子蠕动效应进行了研究。用SQUID磁强计测量了厚度分别为2．4nm、6．0nm、10．8nm和40．0nm的YBCO超导超薄膜样品和厚度为200nm和YBCO薄膜样品的磁化驰豫性质。通过对样品磁化驰豫性质的分析我们在YBCO超导超薄膜样品中以观察到明显的磁通的宏观量子蠕动效应。各样品发生量子蠕动效应的温度Tct在8－15K之间，大大高于以前人们在YBCO单晶样品中观察到的1K的结果。     

银薄膜对光学基底表面粗糙度及光散射的影响

为了研究金属银薄膜与光学基底表面粗糙度和光散射的关系,提出了通过对光学薄膜矢量散射公式积分来获得界面粗糙度完全相关模型和完全非相关模型下其表面的总反射散射的方法．理论计算了光学基底上两种模型在不同厚度银膜下的总反射散射和双向反射分布函数．结果表明,当沉积在光学基底上的银薄膜的厚度大于80nm后．两种模型下计算的银薄膜的表面总反射散射都等于基底的总积分散射,银薄膜能较好地复现出基底的粗糙度轮廓．实验研究表明为了复现基底的粗糙度,银薄膜的最佳厚度应在80～160nm之间．     

GdFeCo/DyFeCo交换耦合两层薄膜磁化方向转变的研究

用磁控溅射法制备了GdFeCo/DyFeCo交换耦合两层薄膜，对交换耦合两层薄膜变温磁化方向进行了研究.结果表明读出层GdFeCo随温度上升从平面磁化转变成垂直磁化，转变过程中主要受饱和磁矩(M_s)的影响.在GdFeCo的补偿温度附近，读出层的磁化强度近于零，退磁场能减小，并在交换耦合的作用下，使读出层的磁化方向发生转变，制备的交换耦合两层薄膜具有中心孔磁超分辨效应. 关键词： 磁光记录 交换耦合两层薄膜 磁化     

原子力显微镜对TeOx薄膜中短波长静态记录点结构的分析

以真空蒸镀法在K9基底上制备了TeOx单层薄膜,采用特定的定位方法,使用原子力显微镜对不同记录功率下薄膜中短滤长静态记录点（514．5nm)的结构进行了分析。实验结果表明薄膜具有良好的记录灵敏性,在记录功率1．5mW时就可产生较高的反射率对比度,记录点具有明显的凹陷和凸起结构,随着记录功率的提高,凹陷和凸起增强,记录点增大。记录点的形态结构和记录前后反射率对比度是直接相关的。研究揭示了原子力显微镜在提高薄膜存储特性如信噪比,存储密度等方面的分析功能。     

BR—D96N光存储读出特性的实验研究

细菌视紫红质（bacteriorhodopsin，简称BR）是嗜盐菌细胞膜内的一种光敏蛋白质。BR薄膜材料具有优异的光循环特性和光致变色特性，可作为信息存储材料。本文讨论了BR所记录图像的对比度与读出光波长变化之间的关系。实验中利用YAG激光器二倍频532nm激光作为图像记录光，白光光源通过单色仪选出单色光作为图像读出光，观察BR膜所记录图像对比度随读出光波长变化趋势，并利用图像灰度积分的方法得到记录图像对比度变化曲线。读出光在470nm-620nm波长范围内，读出为正像；460nm波长附近，图像消失；380nm-450nm波长范围内，图像出现反转。     

两种双光束超分辨数据写入机理的比较

比较了基于光激发-光抑制(SPIN)和受激辐射损耗(STED)的两种双光束超分辨数据写入技术的机理,为基于STED的超分辨数据写入技术建立了动态物理模型,研究其光致聚合过程中的工作机制,并模拟了基于SPIN和STED的双光束超分辨数据写入技术在记录点尺寸和分辨率方面的差异。结果表明:基于STED的双光束超分辨数据写入技术具有无需抑制剂、原理简单的优势,但其需要第二束辅助光的强度较大且对聚合作用的抑制效率低,在多点写入情况下点的尺寸变大,记录均匀性变差。基于SPIN的双光束超分辨数据写入技术所需能量小,多点记录时引发剂分子消耗将抵消抑制剂分子消耗带来的影响,整体均匀性和稳定性好。因此基于SPIN的双光束超分辨数据写入技术在超高密度存储领域应用前景更好。     

Low-Power Super-resolution Readout with Antimony Bismuth Alloy Film as Mask layer

Sb-Bi alloy flms are proposed as a new kind of super-resolution mask layer with low readout threshold power. Using the Sb-Bi alloy film as a mask layer and SiN as a protective layer in a read-only memory disc, the superresolution pits with diameters of 380 nm are read out by a dynamic setup, the laser wavelength is 780 nm and the numerical aperture of pickup lens is 0.45. The effects of the Sb-Bi thin film thickness, laser readout power and disc rotating velocity on the readout signal are investigated. The results show that the threshold laser power of super-resolution readout of the Sb-Bi mask layer is about 0.5 m W, and the corresponding carrier-to-noise ratio is about 20 dB at the film thickness of 50nm. The super-resolution mechanism of the Sb-Bi alloy mask layer is discussed based on its temperature dependence of reflection.     

Super-resolution readout property of bismuth-doped antimony-based thin film as a functional mask for read-only memory

Bismuth-doped antimony-based (Sb_100?x Bi _x , x=2.46) thin films were presented as a functional mask for super-resolution readout of read-only memory (ROM). The pit size of the ROM was 390?nm, and super-resolution readout was realized on a dynamic tester with laser wavelength of 780?nm and the numerical aperture of the focusing objective lens of 0.45. The carrier-to-noise ratio (CNR) of 22?dB, readout threshold power of 0.8?mW and super-resolution readout cycles of 2×10⁴ was achieved. The influence of film thickness and readout power on CNR was investigated. The reflectivity and transmittance of the film with different temperature at wavelength of 780?nm were detected, and the super-resolution mechanism of the bismuth-doped antimony-based thin films as the functional mask layer was discussed.     

Readout of super-resolution marks with Ti thin film

Using Ti as the super-resolution reflective film to replace the Al reflective layer in conventional read-only optical disk, the recording marks with a diameter of 380 nm and a depth of 50 nm are read out in a dynamic testing device whose laser wavelength is 632.8 nm and numerical aperture of the lens is 0.40. The optimum Ti thin film thickness is 18 nm and the corresponding signal-noise-ratio is 32 dB.     

Read—out of a read—only super—resolution optical disc with a Si mask

A novel read-only super-resolution optical disc structure (substrate/mask layer/dielectric layer) is proposed in this paper. By using a Si thin film as the mask layer, the recording pits with a diameter 380nm and a depth 50nm are read out on the dynamic measuring equipment; the laser wavelength α is 632.8nm and the numerical aperture is 0.40. In the course of reproduction, the laser power is 5mW and the rotation velocity of the disc is 4m·s^-1. The optimum thickness of the Si thin film is 18nm and the signal-to-noise ratio is 32dB.     

Shrinkage of picosecond laser beam by plasma reflection in super-resolution near-field structure of SiN/Sb/SiN thin film

The transmittive and reflective Z-scan technique is used with a 10 Hz, frequency doubled, Q-switched, and mode-locked Nd:YAG laser to verify that the reflectivity of the super-resolution near-field structure of an SiN/Sb/SiN thin film increases as incident intensity decreases. This intensity-dependent reflection, called nonlinear reflection, reflects a TEM(00) mode laser beam more strongly at its periphery than at its center and so shrinks the transmitted laser beam. The observed nonlinear reflection is attributed to laser-induced change of carrier densities in Sb, to justify quantitatively the experimental results.     

基于低维相变薄膜的显示器件光学性质的研究

采用传输矩阵模型研究了基于低维相变薄膜的显示器件的光学特性与器件结构的关系。显示器件的类型有反射型和透射型,器件结构的关键参数包括Ge_2Sb_2Te_5(GST)层的厚度、ITO层的厚度、GST层的晶态与非晶态的变化。结果表明:对于反射型器件,ITO层的厚度对器件的反射光谱影响较大,可以通过改变ITO层的厚度达到改变器件颜色的效果;GST层的厚度为12 nm时,GST的晶态与非晶态的变化使器件有最好的颜色对比度且消耗较低的电功率。对于透射型器件,通过使用超薄的GST薄膜,器件的透明度可以保持很高,器件的透明度在GST的厚度超过几纳米后迅速下降。     

Stress evolution and lattice distortion induced by thickness variation and lattice misfit in La0.67Sr0.33MnO3−δ films

La_0.67Sr_0.33MnO_3?δ thin films with different thicknesses are prepared in order to investigate the structural variation induced by film thickness and lattice misfit. The X-ray diffraction results show the in-built stress evolution from a full strained thin layer (～10 nm) to a completely relaxed thick layer (～150 nm), which can be well explained by the Poisson effect. Raman spectroscopy measurements reveal the complicated correlation between the Jahn–Teller (JT) distortion and film thickness. Important octahedron modes reflecting JT distortion are completely caused by the relaxed layer. It is observed that broad JT bands are formed in the films with large thickness of the relaxed layer and the residual stress in the layer leads to an obvious blue shift. In contrast, for films with the thin relaxed layer, JT modes are present as a sharper structure and move to low frequency, indicating towards a much better oxygen stoichiometry.     

一种透过率随入射角近似线性变化的F-P标准具设计

为了由非机械扫描式F-P标准具的透过率得到来袭激光的入射角,设计了一种透过率随入射角近似线性变化的F-P标准具。把薄膜光学原理应用于F-P标准具的设计之中,考虑了斜入射条件下,特别是大入射角下,增透膜和干涉腔反射层特性参数变化对其透过率的影响,针对1.06μm激光,经过仿真设计,确定了F-P标准具主要参数。反射板选用K9玻璃,反射层采用单层ZnS膜时,腔长(475±5)nm,膜厚(65±5)nm,膜层垂直反射率20.7%～24.0%,对应标准具的透过率与入射角之间线性关系为T=-52.23θ+87.92,透过率非线性误差±5%;采用Ag膜时,腔长(460±10)nm,膜厚(3.80±0.15)nm,膜层垂直反射率22.4%～24.8%,T=-52.28θ+82.05,透过率非线性误差±4%。但具体的实现形式和制作工艺有待进一步研究。     

Determination and analysis of the optical constants of thin films of nickel(II) and copper(II) hydrazone complexes by spectroscopic ellipsometry

Thin films of four nickel(II) and copper(II) hydrazone complexes, which will hopefully be used as recording layers for the next-generation of high-density recordable disks, were prepared by using the spin-coating method. Absorption spectra of the thin films on K9 optical glass substrates in the 300–700 nm wavelength region were measured. Optical constants (complex refractive indices N) and thickness d of the thin films prepared on single-crystal silicon substrates in the 275–675 nm wavelength region were investigated on a rotating analyzer-polarizer scanning ellipsometer by fitting the measured ellipsometric angles (Ψ(λ) and Δ(λ)) with a 3-layer model (Si/dye film/air). The dielectric functions ε and absorption coefficients α as a function of the wavelength were then calculated. Additionally, a design to achieve high reflectivity and optimum dye film thickness with an appropriate reflective layer was performed with the Film Wizard software using a multilayered model (PC substrate/reflective layer/dye film/air) at 405 nm wavelength. PACS 81.05.L; 78.20.Ci; 78.20.-e