Active Plasmonic Materials and Devices

技术：这项研究项目涉及活性等离子体材料和原型装置。等离子体激元主要集中在无源金属介质结构上，以控制波在平面波导、亚波长尺度小孔和纳米粒子阵列中的色散和传播。虽然被动等离子体材料使等离子体组件能够以电路状网络相互连接，但如果能够实现主动等离子体材料/器件，等离子体组件和网络将有可能实现更大的功能。这一方法的核心是合成和表征新的等离子体材料，这些材料可能使等离子体发射、非线性和增益成为潜在的等离子体器件应用。其目标是形成材料基础，使紧凑的等离子体源和可用于集成到包含线性和非线性元件的纳米光子电路的非线性等离子体和纳米光子组件用于基于芯片的光学开关、成像和分子光谱学等应用。概念和材料研究涉及三个具体的应用领域。一是基于等离子体孔阵列和纳米粒子阵列传输的电光和非线性光调制实现超致密亚波长光子开关的材料研究。第二个领域是表面等离子体发射源的实现，包括具有等离子体增强光发射和光谱调谐自发辐射的发光结构，以及纯束缚等离子体产生材料的配置。第三个领域是环形布拉格谐振器表面等离子体激元腔中亚波长模体积内等离子体模的设计和限制。对这些结构的研究有望对表面电磁波在金属界面的传播和散射的性质，以及受金属纳米结构附近的局域场强烈扰动的量子点和偶极发射体的辐射发射特性产生新的见解。该方法包括理论活动和实验活动。理论工作将侧重于使用指导等离子体结构设计的有限差分、时间域和光束传输方法的分析建模和全场电磁模拟。实验工作将集中在发展有源等离子体结构制造，包括等离子体腔的光刻制造，有源半导体纳米晶体介质(Si，CdSe和IV-VI铅盐PbS和PbSe)的集成。非技术性：该项目解决具有高度技术相关性的材料科学专题领域的基础研究问题。这项研究将在基础水平上为潜在的下一代电子/光子设备的新理解和能力贡献基本材料科学知识。该计划的一个重要特点是通过在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。该项目包括：i)对新兴等离子体和纳米光子学领域的研究生研究人员进行培训；ii)通过加州理工学院夏季本科生研究向少数族裔本科生进行教育推广；iii)通过将于2006年夏季首次举行的新成立的戈登等离子体研究会议，在世界等离子体领域传播研究成果。研究生研究培训涉及材料科学和表面等离子体发射源的应用物理以及等离子体材料中的非线性现象。少数族裔本科生将通过加州理工大学的少数族裔本科生奖学金计划、GradPview计划以及加州理工大学和加州州立大学洛杉矶分校之间的材料伙伴关系互动来确定。首席研究员将担任新的等离子体戈登会议的副主席，该会议的目标是通过促进科学前沿的跨学科陈述和讨论来推动等离子体领域的发展。

Technical: This research project addresses active plasmonic materials and prototype devices. Plasmonics has focused largely on passive metallodielectric structures to control wave dispersion and propagation in planar waveguides, subwavelength scale apertures and nanoparticle arrays. While passive plasmonic materials enable plasmonic components interconnected in circuit-like networks, greater functionality will be possible in plasmonic components and networks if active plasmonic materials/devices can be realized. The approach centers on synthesis and characterization of new plasmonic materials which may enable plasmon emission, nonlinearity and gain for potential plasmonic device applications. The goal is to form the materials foundation for enabling compact plasmonic sources and nonlinear plasmonic and nanophotonic components useful for integration into nanophotonic circuits containing linear and nonlinear elements for applications such as chip-based optical switching, imaging, and molecular spectroscopy. The concepts and materials research addresses three specific application areas. The first is materials research for realization of ultracompact subwavelength photonic switches based on electro-optical and nonlinear optical modulation of plasmonic hole-array and nanoparticle array transmission. The second area is realization of surface plasmon emission sources, including light-emitting structures featuring plasmon-enhanced light emission and spectrally-tuned spontaneous emission as well as purely bound plasmon-generating material configurations. The third area is the design and confinement of plasmonic modes within subwavelength mode volumes in annular Bragg resonator surface plasmon cavities. Investigation of these structures is expected to yield new insights about the nature of surface electromagnetic wave propagation and scattering at metal interfaces and the radiative emission properties of quantum dots and dipole emitters strongly perturbed by local fields near metallic nanostructures. The approach includes theoretical and experimental activities. Theoretical work will focus on analytic modeling as well as full-field electromagnetic simulations using finite difference time domain and beam propagation methods that guide the design of plasmonic structures. Experimental work will focus on developing active plasmonic structure fabrication, including lithographic fabrication of plasmonic cavities, integration of active semiconductor nanocrystal media (Si, CdSe and the IV-VI lead salts PbS and PbSe). Non-Technical: The project addresses basic research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new understanding and capabilities for potential next generation electronic/photonic devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The project includes i) training of graduate researchers in the emerging areas of plasmonics and nanophotonics ii) educational outreach to minority undergraduate students via summer undergraduate research at Caltech and iii) research dissemination in the worldwide plasmonics community via a newly-founded Gordon Research Conference on plasmonics, to be held for the first time in summer 2006. Graduate research training involves materials science and applied physics of surface plasmon emission sources and nonlinear phenomena in plasmonic materials. Minority undergraduate students will be identified through Caltech's Minority Undergraduate Fellowship program, GradPreview program and via interactions with the Materials Partnership between Caltech and California State University Los Angeles. The principal investigator will serve as Vice-Chair of the new Plasmonics Gordon Conference, whose goal is to advance the plasmonics field through stimulating interdisciplinary presentation and discussion at the frontiers of science.