SGER: Designing Active Nanostructures from Passive Metallic Films

技术：该提案描述了对金属薄膜进行纳米级孔阵列穿孔的基础研究。PI计划研究如何在薄贵金属薄膜上创建结构的简单但革命性的程序可以将平面被动薄膜转变为有源纳米结构。具体来说，PI建议研究贵金属薄膜中这些小孔的大小、形状和排列如何在操纵光方面发挥积极作用。为了表征这些纳米结构薄膜的特性，PI计划测量相同薄膜的局部和集体光学行为。因此，完整的近场和远场研究的金属薄膜的孔可以进行划定之间的表面等离子体激元激发，传播和干扰。该项目集成了一种新的方法来制造纳米孔阵列在薄金属薄膜与先进的工具，以表征其光学特性。这种组合允许PI解决表面等离子体如何通过孔阵列介导增强传输的问题，因为PI可以将表面等离子体的近场图像与其远场光谱相关联。对相同金属薄膜的这种局部和集体研究将使PI能够区分表面等离子体激元和局部表面等离子体激元激发、传播和干涉。以前的亚波长孔阵列的研究只集中在他们的远场特性，而不是对潜在的近场现象，这是关键的增强光传输的机制提出。PI我们将探索三种相互关联但不同的方式，纳米孔金属薄膜可以作为活性纳米结构。这些战略包括：（i）在具有宽间隔孔阵列的膜上将SP操纵成驻波图案，（ii）增强和准直通过紧密间隔孔阵列的光透射，以及（iii）通过改变偏振来控制传播通过膜的光的颜色和局部模式。非技术性：研究将允许作出重要贡献，不仅为理解光是如何通过孔传输，但也将使人们能够设计不同的结构，在金属薄膜的潜力，表现出其他有趣的和意想不到的光学性能。这项工作可以提供洞察这个十年之久的问题，以及推动其他有趣的现象，除了表面等离子体，如伍德的异常，衍射和波导模式的孔阵列。外联活动将主要集中于将研究活动纳入课堂，并为纳米科学和光子学领域的7-16年级制定内容。具体而言，由NSFNUE方案赞助的一个新的以研究为基础的课程将于2006年冬季和春季提供。此外，PI还为NSF纳米级学习和教学中心（NCLT）的教师教育和专业发展做出贡献。

TECHNICAL: This proposal describes fundamental studies of thin metallic films perforated with arrays of nanoscale holes. PI plans to investigate how a simple but revolutionary procedure to create structure on thin noble metal films can transform flat passive films into active nanostructures. Specifically, PI proposes to investigate how the size, shape, and arrangement of these small holes in noble metal films can play an active role in manipulating light. To characterize the properties of these nanostructured films, PI plans to measure the local and collective optical behavior of the same films. Therefore, complete near-field and far-field studies of metallic films of holes can be carried out to delineate among surface plasmon excitation, propagation and interference. The project integrates a new approach to fabricate nanohole arrays in thin metal films with sophisticated tools to characterize their optical properties. This combination allows PI to address the question of how surface plasmons can mediate enhanced transmission through hole arrays because PI can then correlate the near-field images of surface plasmons with their far-field spectra. Such local and collective studies on the same metallic films will enable PI to distinguish among surface plasmon polariton and localized surface plasmon excitation, propagation, and interference. Previous studies of subwavelength hole arrays have focused solely on their far-field properties and not on the underlying near-field phenomena, which is critical in the proposed mechanism for enhanced optical transmission. PI we will explore three inter-related but distinct ways that nanohole metallic films can function as active nanostructures. These strategies include: (i) manipulating SPs into standing wave patterns on films with arrays of widely spaced holes, (ii) enhancing and collimating the light transmission through arrays of closely spaced holes, and (iii) controlling the color and localized modes of light propagating through the films by changing the polarization. NON-TECHNICAL: Research will allow important contributions to be made not only for understanding how light is transmitted through the holes but will also enable one to design different structures in the metal films with potential to exhibit other interesting and unexpected optical properties. This work can provide insight into this decade-old problem as well as push forward other interesting phenomena in hole arrays besides surface plasmons, such as Wood's anomalies, diffraction, and waveguide modes. Outreach activities will concentrate primarily on the integration of research activities into the classroom and the development of content for 7-16 grade levels in the area of nanoscience and photonics. Specifically, a new research-based course for sophomores, sponsored by the NSFNUE program is being offered in Winter and Spring 2006. In addition, PI is contributing to the education and professional development of teachers in the NSF-Nanoscale Center for Learning and Teaching (NCLT).