表面等离激元波导中的量子信息传输

发布时间：2018-05-29 17:35

本文选题：表面等离激元 + 线性光学损耗　；参考：《中国科学技术大学》2017年博士论文

【摘要】：表面等离激元近年来得到了越来越多的关注和研究,得益于其能把电磁场束缚在金属-介质界面附近亚波长尺度范围内。这种超强的光场模的空间压缩可以减小集成光学器件的尺寸、提高光学系统的空间分辨率并且增强光与物质的相互作用。然而受限于实验技术、微纳加工和电磁波计算模拟,对表面等离激元量子特性的实验研究直到近二十年才得到发展。在基于光学的量子信息研究中,除了光子的优良特性,光子的两个特性一直困扰着本领域的发展。一是光学的模式体积受限于光学衍射极限,导致光学器件的尺寸无法缩小,不利于集成化和大规模扩展化;二是光子与光子、光子与物质的相互作用很弱,很难为量子操作提供足够的非线性。表面等离激元为解决这些问题提供了可行性方案,表面等离激元的超小模式可提高光学的集成化程度并增强与量子发光体的相互作用。本人在博士期间的主要研究内容是利用表面等离激元在亚波长尺度的波导中传输量子信号,并开发在量子信息领域中的应用。本文的主要内容包括:1.在600nm×600nm的电介质加载表面等离激元波导中观测到了单个表面等离激元之间的Hong-Ou-Mandel干涉,工作波长为1550nm,干涉可见度为95.7%。这证明了,表面等离激元和光子一样表现为玻色子的行为,为表面等离激元在量子信息领域中的进一步应用打下了基础。2.分析损耗在线性量子光学集成回路中的的效应。一般,损耗被仅仅看成影响光学回路效率的因素,可以被等效地归结为探测器的低探测效率,而所需的量子操作都可以通过后选择来完成。我们把损耗分为线性独立的损耗和分享的共同损耗,研究在波导耦合过程中,损耗对集成光学器件性质的影响机制并计算共同损耗对集成的光学量子逻辑门保真度的影响。3.实验实现量子偏振纠缠的双光子对在160nm半径的金属银纳米线波导中的传输。我们发明了光纤集成的表面等离激元探针,通过绝热耦合实现光子与表面等离激元之间的高效率转化。我们验证,该探针可以在不受光学衍射极限的尺度下维持单光子自身的偏振和光子对之间的纠缠特性。'4.实验实现了表面等离激元探针对量子点荧光的收集。我们利用光纤集成的表面等离激元探针与量子点相互作用,量子点直接自发辐射荧光到探针中,直接通过光纤导出而不需要复杂的显微镜光路。该方法有望同时实现量子点的荧光增强、直接激发和收集。5.提出基于光子之间关联的损耗探测方案,证明光子之间的关联可以提高对损耗参数估计的精确度,并在实验中验证了光子之间的关联可以用于提高光学显微镜的信噪比。这种显微镜可以结合表面等离激元探针同时实现超分辨和超灵敏的参数估计。
[Abstract]:In recent years, surface isotherms have been paid more and more attention, thanks to their ability to bind the electromagnetic field to the sub-wavelength scale near the metal-dielectric interface. The space compression of this super light field mode can reduce the size of integrated optical devices, improve the spatial resolution of optical systems and enhance the interaction between light and matter. However, limited by the experimental techniques, micro and nano fabrication and electromagnetic wave simulation, the experimental study of the quantum properties of surface isotherms has not been developed until the last 20 years. In the study of quantum information based on optics, in addition to the excellent properties of photons, the two characteristics of photons have been puzzling the development of this field. One is that the mode volume of optics is limited by the limit of optical diffraction, which results in the size of optical devices cannot be reduced, which is not conducive to integration and large-scale expansion, and the other is that the interaction between photons and photons is very weak, and the interaction between photons and matter is very weak. It is difficult to provide sufficient nonlinearity for quantum operations. Surface isophosphors provide a feasible solution to these problems. The ultra-small mode of surface isophosphors can enhance the degree of optical integration and enhance the interaction with quantum luminescence. My main research work during my Ph. D period is to use surface isotherms to transmit quantum signals in subwavelength waveguides and to develop applications in the field of quantum information. The main contents of this paper include: 1. The Hong-Ou-Mandel interference between the single surface isophosphors was observed in the dielectric loaded surface isophosphor waveguide of 600nm 脳 600nm. The operating wavelength was 1550nm and the visibility of the interference was 95.7nm. It is proved that the surface isophosphors behave as bosons as photons, which lays the foundation for the further application of surface isotherms in the field of quantum information. The effect of loss in linear quantum optical integrated circuit is analyzed. In general, the loss is only regarded as the factor affecting the efficiency of the optical loop, which can be reduced to the low detection efficiency of the detector, and the required quantum operation can be completed by the selection of the back. We divide the loss into linear independent loss and shared common loss. We study the influence mechanism of loss on the properties of integrated optical devices during waveguide coupling and calculate the effect of common loss on fidelity of integrated quantum logic gates. Quantum polarization entangled two-photon pairs are experimentally propagated in a metal silver nanowire waveguide with 160nm radius. We have invented a surface isoexciton probe integrated with optical fiber. The high efficiency conversion between photons and surface isopitons can be realized by adiabatic coupling. We verify that the probe can maintain the polarization of the single photon itself and the entanglement between the photon pairs at the scale not subject to the optical diffraction limit. The collection of quantum dot fluorescence by surface isophosphorus probe has been realized experimentally. In this paper, we use the optical fiber integrated surface probe to interact with the quantum dot, and the quantum dot directly emits spontaneous fluorescence into the probe, which is derived directly through the optical fiber without the need for complicated optical path of the microscope. This method is expected to simultaneously achieve fluorescence enhancement of quantum dots, direct excitation and collection of .5. A loss detection scheme based on the correlation between photons is proposed. It is proved that the correlation between photons can improve the accuracy of the estimation of loss parameters and the correlation between photons can be used to improve the signal-to-noise ratio of optical microscopes. This kind of microscope can be combined with the surface isobaric probe to realize the super-resolution and hypersensitive parameter estimation at the same time.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O431.2;TN25

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