共查询到20条相似文献,搜索用时 46 毫秒
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一种猫眼列阵赝相位共轭镜的研究 总被引:1,自引:1,他引:0
本文介绍一种由一块透镜网格板和一块平面反射镜组成的后向式猫眼列阵赝相位共轭镜(PPCM),并研究了它的视场大小、分辨率及信息自由度. 相似文献
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本文应用4×4矩阵方法,研究了光学元件列阵的各光学单元之间的共焦问题,给出了较好的近似理论公式,它包括了傍轴光线近似的特殊情况。 相似文献
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光学并行高速缓冲存储列阵和随机暂存列阵,是数字光学处理机中的重要部件。本文提出了一种简单的光学并行高速缓冲存储列阵系统,并在实验中完成了光信号列阵的随机存、取全过程。 相似文献
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用浑沌序列构造相位列阵加密和解密光学图象 总被引:4,自引:2,他引:2
本文提出了一种用浑沌序列构造相位列阵加密和解密光学图象的方法,并对该光学系统进行了计算机模拟。由浑沌序列对初始条件的敏感性使保密性能提高,同时它又是由确定性系统产生的,故可以完全被重构。将它和纯相位空间光调制器结合起来能对光学图象实时进行相位加密和解密,不仅使密匙更难被非法破译,而且压缩了其数据量。结果表明该方法较随机相位掩模方法具有许多优越性且易于实际应用。 相似文献
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大尺度相干结构的光学特性研究 总被引:3,自引:1,他引:2
根据大气近地面层对流湍池的实验结果,提出了一种用于描述大尺度相干结构的立体模型——椭球结构模型。计算并分析了该大尺度相干结构对光传输波前相位结构函数的影响,且和小尺度湍流结构作了比较。对于相同的参数,光线平行于间断面时造成的影响大于垂直于间断面;一般情况下,影响都很小;但当光线平行穿过具有三角波模型结构的间断面时可能产生较大的影响。 相似文献
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噪音对光学图象浑沌相位列阵加密和解密的影响 总被引:1,自引:0,他引:1
本文提出了一种用浑沌相位列阵对光学图象加密和解密的方法,并重点分析了加法高斯白噪音对光学图象浑沌相位列阵加密和解密的影响.通过计算机模拟发现加密后的图象与原图象相比,抗振幅噪音的能力增强,而抗相位噪音的能力下降.在一定信噪比范围内,相位噪音是影响解密图象质量的主要因素. 相似文献
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Here we introduce a facile method to fabricate patterned indium tin oxide (ITO) thin films via selective laser ablation at ambient conditions. By scanning the ITO thin films with focused Nd: YAG pulsed laser, the ITO thin films were selective ablated and patterned without using any conventional chemical etching or photolithography steps. Then we investigated the effects of scanning rate for the structure, morphology and optical properties of patterned ITO thin film. These results indicate that the epsilon-near-zero (ENZ) wavelength of ITO thin films can be tuned from 1100 nm to 1340 nm by adjusting the period of the micro-hole array in microstructure. The nonlinear absorption response of patterned ITO films was about 2.85 time than of the as-deposited ITO thin film. Additionally, the results of the Finite-Difference Time-Domain (FDTD) simulation are in good agreement with those of the experiments. 相似文献
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Imaging properties of photon sieve with a large aperture 总被引:1,自引:0,他引:1
Zhong Gao Xiangang Luo Junxian Ma Yongqi Fu Chunlei Du 《Optics & Laser Technology》2008,40(4):614-618
We report the optimization design and experimental results for the imaging properties of a photon sieve, which is formed on a layer of metal film supported by a thin glass substrate. As an example, we considered a micro-optical element with parameters of diameter D=50 mm, 3,564,290 hole number, and 10 μm minimum micro-hole diameter, which was designed and fabricated by means of surface machining technique in the lab. To evaluate its imaging performance, both on-axis and off-axis imaging experiments were carried out using the element. Compared to a Fresnel zone plate lens with the same feature size, the photon sieve has super imaging performance. Some quantitative analyses and initial qualitative explanations were given for the imaging characteristics. 相似文献
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亚波长直径光纤的光学传输特性及其应用 总被引:2,自引:0,他引:2
通过高温下的物理拉伸方法,可以直接将玻璃材料拉细成亚波长或纳米直径的光纤。所获得的光纤具有很好的直径均匀度和表面光滑度,可用于低损耗光传输,并可在可见和近红外光学传输中表现出强光场约束、倏逝波传输和大波导色散等特性,在光通信、传感和非线性光学等领域具有良好的应用前景。 相似文献
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提高各通道输出光信噪比,进行了复用体全息光栅的优化设计研究。推导了适用于角度放大器的多路复用体光栅耦合波理论,并与单路耦合波理论进行了比较。针对复用体光栅中的串扰问题,研究了调整光栅结构参数优化串扰的规律,并进行了实验验证。研究结果表明:当相邻两路体光栅的布拉格角间隔小于二者角度选择半宽之和时,相互间串扰较强,必须使用多路耦合波理论描述复用体光栅中波的衍射行为。调整相邻路体光栅的矢量倾斜角间隔、减小光栅周期和增加光栅厚度都可以降低串扰,其中调整矢量倾斜角和光栅周期优化效果明显但会降低角放大率,增加介质厚度不影响角放大率但需要厚度增加数倍才有效。 相似文献
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采用纳米球刻蚀(nanosphere lithography)技术,以自组装的聚苯乙烯纳米小球(polystyrene,PS小球)的单层膜为掩模,制备出二维有序的CdS纳米阵列.利用扫描电子显微镜(SEM)对样品结构进行了表征,用紫外—可见分光光度计对样品光学性质进行了分析.结果表明:制备的二维CdS纳米阵列是高度有序的,且与作为掩模的纳米小球的原始尺寸及排布结构一致;禁带宽度为2.60eV,相对于体材料的2.42eV,向短波长蓝移了0.18eV,表现出CdS材料在纳米结构点阵中的量子尺寸效应;CdS纳米
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纳米球刻蚀
二维CdS纳米有序阵列 相似文献
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Fabrication and optical properties of platinum nanowire arrays on anodic aluminium oxide templates 下载免费PDF全文
Arrays of Pt nanowires, fabricated by electrodepositing Pt metal into nanoporous anodic aluminium oxide (AAO) templates, exhibit a preferable optical absorption band in the ultraviolet-visible (UV-VIS) spectra and present a blueshift as the wire aspect ratio increases or its radius decreases. This type of optical property of Pt nanowire/porous alumina composites has been theoretically explored using Maxwell-Garnett (MG) effective medium theory. The MG theory, however, is only applicable to nanowires with an infinitesimally small radius relative to the wavelength of an incident light. The nanowire radius is controlled by the pore radius of the host alumina, which depends on anodizing conditions such as the selected electrolyte, anodizing time, temperature and voltage. The nanowire aspect ratios depend on the amount of Pt deposited into the nanopores of AAO films. The optical absorption properties of the arrays of Pt nanowires with diameters of 24, 55 and 90 nm have been investigated by the UV-VIS spectra, which show that the extinction maximum (λmax) shifts to shorter wavelength side as the wire aspect ratio increases or its radius decreases. The results are qualitatively consistent with those calculated based on the MG theory. 相似文献
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Guoquan Zhou 《Optics Communications》2010,283(7):1236-1243
Based on the generalized integral formula and the convolution theorem of the Fourier transform, an analytical propagation formula of a Lorentz-Gauss beam passing through a misaligned paraxial optical system is derived. As numerical examples, the propagation properties of a Lorentz-Gauss beam through a misaligned thin lens with the lateral displacement and the angle displacement are graphically illustrated, respectively. The influences of the lateral displacement and the angle displacement of the misaligned thin lens on the normalized light intensity and the phase distributions are also examined, respectively. 相似文献