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Design of broadband achromatic metasurface device based on phase-change material Ge2Sb2Te5
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Shuyuan Lv 《中国物理 B》2022,31(12):124206-124206
Based on the phase-change material Ge2Sb2Te5 (GST), achromatic metasurface optical device in the longer-infrared wavelength is designed. With the combination of the linear phase gradient GST nanopillar and the adjustment of the crystalline fraction m value of GST, the polarization insensitive achromic metalenses and beam deflector metasurface within the longer-infrared wavelength 9.5 μm to 13 μm are realized. The design results show that the achromatic metalenses can be focused on the same focal plane within the working waveband. The simulation calculation results show that the full-width at half-maximum (FWHM) of the focusing spot reaches the diffraction limit at each wavelength. In addition, the same method is also used to design a broadband achromatic beam deflector metasurface with the same deflection angle of 19°. The method proposed in this article not only provides new ideas for the design of achromatic metasurfaces, but also provides new possibilities for the integration of optical imaging, optical coding and other related optical systems. 相似文献
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用反向调制照明法分析光栅成像效应 总被引:2,自引:1,他引:1
提出了用反向调制照法明分析光栅成像效应的观点,研究了光栅系统的反向衍射干涉效应,成功地揭示了泰伯效应与劳效应的内在联系,并在白光双光栅衍射干涉的“消色效应”的基础上获得了白光扩展光源照明下白光光栅成像效应和具有实用意义的四光栅干涉系统。 相似文献
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S.J. Dobson 《Optics & Laser Technology》1990,22(5)
Some flight simulators, known as multi-window simulators, are required to produce a wide field of view obtained by viewing a number of TV monitors through separate collimators. The extra requirement for shadowgraph projection of additional cueing information such as the sky and the horizon on to a dome above the pilot's head means that it is impossible to use the conventional concave mirror collimator. An alternative system is the Pancake Window but this gives insufficient light output.This paper describes the design of a three-element, all-plastic, one aspheric surface, achromatic, collimating lens which overcomes these problems. It is based on work carried out for the Royal Aircraft Establishment. 相似文献
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一种新的消色像全息术 总被引:3,自引:2,他引:1
本文从全息再现像的物像关系出发,对准像面情况下,像点随波长及参考光源扩展的变化进行了研究.阐明了利用散射线光源作参考光使全可见光范围内的像叠加在一起,产生消色像全息图的基本思想,并引入了消色像域的概念.考虑到点基元全息图尺寸及人眼瞳孔对成像光束的限制,白光再现时,可以获得清晰、明亮、具有一定景深和相当视场范围的消色再现像. 相似文献
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Let G be a simple graph. The achromatic number ψ(G) is the largest number of colors possible in a proper vertex coloring of G in which each pair of colors is adjacent somewhere in G. For any positive integer m, let q(m) be the largest integer k such that ≤ m. We show that the problem of determining the achromatic number of a tree is NP-hard. We further prove that almost all trees T satisfy ψ (T) = q(m), where m is the number of edges in T. Lastly, for fixed d and ϵ > 0, we show that there is an integer N0 = N0(d, ϵ) such that if G is a graph with maximum degree at most d, and m ≥ N0 edges, then (1 - ϵ)q(m) ≤ ψ (G) ≤ q(m). © 1997 John Wiley & Sons, Inc. J Graph Theory 26: 129–136, 1997 相似文献
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使用一种基于二元光学透镜的分光成像及消色差原理的新方法来设计资源卫星的中继光学系统。通过分析二元光学透镜的分光成像原理、消色差原理、衍射效率与阶数和工作波长及设计波长的比之间的关系,又考虑到单独设计制造二元光学透镜的难度,采用折衍混合成像光学系统来拟定资源卫星中继光学系统的设计方案,给出用ZEMAX软件设计的具体结果。设计实例及分析结果表明,包含二元光学透镜的折衍混合成像系统可以很好的实现光谱波段分离,用于资源卫星的光学系统具有一定的适用性。 相似文献
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根据菲涅尔全内反射相变理论,给出了双菱体λ/4消色差器的结构设计、性能分析和测量方法.由有效通光孔径和光线追迹设计出BK7玻璃在波长532 nm时相位延迟λ/4的双菱体的结构,用作532 nm至1 064 nm波长范围的标准λ/4相位延迟器.理论分析了入射角变化和波长变化对双菱体相位延迟的影响,当入射角变化限制在±4.3°以内时,其影响得到补偿;波长从532 nm到1 064 nm产生的误差为-0.65°.采用椭偏法中的消光技术,分别实测了双菱体在532 nm和1 064 nm波长下的相位延迟为:90.08±0.14°和88.99±0.1°,可知两不同波长产生的相位延迟误差为-1.09°. 相似文献