MRI: Design and Development of a Femtosecond Apertureless Near-field Microscope

技术摘要在该项目下，南达科他州矿业与技术学院将设计、建造和优化一台具有飞秒时间分辨率的多功能无孔近场扫描光学显微镜(a-NSOM)。完成的仪器将为SDSM&amp；T带来空间分辨纳米材料和具有亚波长空间分辨率和超快时间分辨率的系统的光谱性质的能力。A-NSOM和相关仪器将使SDSM&amp；T和南达科他大学的教职员工能够开展合作研究，包括以下纳米光学研究：纳米结构对太阳能电池中发光上转换和中间带吸收的影响，这两项对所谓的第三代太阳能转换设备都很重要；半导体表面用于光电化学制氢的化学修饰的影响；以及等离子体纳米粒子复合材料的电磁场增强，这对于增强全光光子开关材料的非线性响应非常重要，并在未来的计算和通信设备中得到应用。这样的合作为理解纳米结构表面的化学和物理提供了一种独特的工具，从而加强了南达科他州大学联盟，该联盟专注于光活性纳米系统(PANS)。这项拟议的工作将通过为南达科他州的学生和教职员工以及本科生提供合作研究机会，进一步建立和支持SDSM&amp；T新成立的、国家支持的纳米科学和纳米工程博士课程。众所周知，材料的许多独特的光学性质是纳米尺度(1-100 nm)结构的结果，但由于衍射限制，经典光学方法无法获得这样的长度尺度。该仪器开发方案的目标是设计、组装和优化一种多功能的、具有飞秒时间分辨率的无孔近场显微镜。这种无孔技术提供了以前所未有的时间(~10f)和空间分辨率(~10 nm)进行全光光谱研究的可能，从而揭示了纳米结构与纳米材料的光学性质之间的重要联系。该仪器将用于合作研究，以开发用于改进太阳能电池、太阳能制氢以及用于超高速光学计算机和通信设备的所有光学开关的新材料。拟议中的仪器的开发将雇用几名本科生，让他们接触到纳米科学和纳米技术方面的机会，并将在SDSM&amp；T的PI教授的纳米光子学课程中展示。SDSM&amp；T维持着一个永久性的美洲原住民推广计划，为南达科他州近7万名美洲原住民服务。参与的PI强烈支持这些努力，并将在旨在招募代表不足的群体进入科学和工程领域的外联计划中利用这些工具。

Technical AbstractUnder this project, a versatile apertureless near-field scanning optical microscope (a-NSOM) with femtosecond temporal resolution will be designed, constructed, and optimized at the South Dakota School of Mines and Technology. The completed instrument will bring to SDSM&T the capability to spatially-resolve spectroscopic properties in nano-materials and systems with subwavelength spatial resolution and ultrafast time resolution. The a-NSOM and associated instrumentation will enable collaborative research between faculty at SDSM&T and the University of South Dakota, including nano-optical studies of: the effect of nanostructure on luminescence upconversion and intermediate band absorption in solar cells, both important for so-called third generation solar energy conversion devices; the effects of chemical modification on semiconductor surfaces for photo-electrochemical hydrogen production; and the electromagnetic field enhancements in plasmonic nano-particle composite materials, important for enhanced nonlinear response in materials for all optical photonic switches with applications in future computation and communication devices. Such collaborations strengthen the South Dakota university consortium, focused on Photo-Active Nano Systems (PANS), by providing a unique tool for understanding the chemistry and physics of nano-structured surfaces. This proposed work will further build and support the newly formed, state supported, Nanoscience and Nanoengineering PhD program at SDSM&T, by enabling collaborative research opportunities for students and faculty in the program, as well as undergraduate science and engineering students in the state of South Dakota.Lay AbstractSpectroscopy is the systematic investigation of the optical properties of materials. It is now known that many unique optical properties of materials are a consequence of structure on the nanoscale (1-100nm), yet such length scales are inaccessible to the methods of classical optics due to the diffraction limit. The goal of this instrument development proposal is to design, assemble and optimize a versatile apertureless near-field microscope with femtosecond time resolution. The apertureless technique offers the potential to perform all-optical spectroscopic investigations with unprecedented temporal (~ 10fs) and spatial resolution (~ 10nm), thereby revealing the important connection between nanostructure and the optical properties of nanomaterials. The instrument will be used in collaborative research to develop new materials for improved solar cells, solar hydrogen production, and all optical switches for use in ultrafast optical computers and communication devices. The development of the proposed instrument will employ several undergraduate students, exposing them to opportunities in nanoscience and nanotechnology, and will be showcased in a course on nanophotonics, taught by the PI at SDSM&T. SDSM&T maintains a permanent Native American outreach program, serving the nearly 70,000 Native Americans in South Dakota. The PI's involved strongly support these efforts, and would utilize the instrumentation in outreach programs aimed at recruiting under-represented groups into science and engineering.