MRI: Acquisition of a Near-Field Optical Microscope with Spectroscopic Capabilities

技术摘要：在本提案中，我们申请资金购买最先进的光学系统，用于执行具有光谱功能的近场扫描光学显微镜（NSOM）。NSOM的前景在于它能够在远低于衍射极限的空间范围内提供波长相关的光学成像；其成像和光谱能力提供结构和成分信息的空间分辨率远高于传统的光学显微镜。因此，NSOM是光学衍射有限系统和高空间分辨率非光谱技术（如原子力显微镜和电子显微镜）之间的重要桥梁。随着从“微”到“纳米”的持续转变，材料在这种空间状态下的表征至关重要。该系统的配置将确保对俄勒冈大学从纳米光子学到生物科学等领域的研究项目做出直接贡献。NSOM的能力将被用于扩展正在进行的关于高度受限金属介电纳米结构中相干光学现象的研究。该系统非常适合于研究等离子体局部化、非线性等离子体和纳米等离子体系统。由于NSOM在有机和生物材料的表征方面也被证明是非常有用的，它将被几个对这些领域感兴趣的研究小组使用。在一个项目中，它将用于研究受体细胞突触活跃区离子通道的空间组织。在一个独立的研究小组中，NSOM将在亚微米水平上促进表面吸附生物分子的光谱成像。在另一个项目中，光导有机半导体中的电荷输运将在单分子水平上进行研究。作为俄勒冈大学多用户表面分析设施的一部分，NSOM将处于最佳位置，以影响大学内外广泛的新兴研究项目，并扩大现有设施的用户基础。【非技术摘要】本提案涉及一个专门的高分辨率显微镜系统的获取，该系统能够提供有关微小结构的结构和组成特征的信息。该仪器可以研究各种各样的系统；一些例子包括非常小的金属颗粒、生物细胞、发光分子和水面上的薄浮油。所有这些系统的统一之处在于它们的尺寸规模——通常约为人类头发宽度的千分之一，有时甚至更小。传统的光学显微镜，如高中科学实验室里的显微镜，无法在如此小的尺度上显示物体的空间特征。这种限制是所有常用的光学系统所固有的，这些系统使用光和透镜来可视化和放大图像。使用这些仪器可以区分的最小空间特征大约是可见光波长的一半，大约是我们感兴趣的研究系统的5到10倍。然而，如果在离样品非常近的地方放置一个微小的光圈（甚至比我们最小的物体还要小！）来代替镜头，那么当光圈被可见光照射时，就有可能拍摄出更精细的特征。这样的系统将允许俄勒冈大学及其附属机构的学生和研究人员阐明新系统的特征，例如自然界已知的最小发光结构，制造超紧凑的电子和光学设备，了解化学污染物如何与其直接环境相互作用，并以前所未有的光学分辨率研究生物细胞结构和功能。

Technical AbstractIn this proposal we request funds to purchase a state-of-the-art optical system for performing Near-field Scanning Optical Microscopy (NSOM) with spectroscopic capabilities. The promise of NSOM lies in its ability to provide wavelength-dependent optical imaging in spatial regimes well below the diffraction limit; its imaging and spectroscopic capabilities offer structural and compositional information at a spatial resolution much higher than traditional optical microscopy. The NSOM therefore comprises a crucial bridge between optical diffraction-limited systems and higher-spatial-resolution non-spectroscopic techniques such as atomic force microscopy and electron microscopy. Characterization of materials in this spatial regime is of paramount importance as the shift from "micro" to "nano" continues. The system will be configured to ensure an immediate contribution to research programs based at the University of Oregon in fields ranging from nanophotonics to biological sciences. The NSOM capabilities will be exploited to extend ongoing research on coherent optical phenomena in highly confining metallodielectric nanostructures. The requested system is ideally suited for investigation of plasmon localization, nonlinear plasmonics active nanoplasmonic systems. As NSOM has also been shown to be of great usefulness in the characterization of organic and biological materials, it will be used by several research groups with interests in these fields. In one project, it will be used to investigate the spatial organization of ion channels at synaptic active zones in receptor cells. In a separate research group the NSOM will facilitate spectroscopic imaging of surface-adsorbed biomolecules at the submicron level. In another project, charge transport in photoconductive organic semiconductors will be investigated at the single molecule level. As part of the multi-user Surface Analytical Facility at the University of Oregon, the NSOM would be optimally positioned to impact a broad range of emerging research programs, both within the university and outside, as well as expand the current facility user base.Non-Technical AbstractThis proposal addresses the acquisition of a specialized high-resolution microscopy system, capable of providing information about the structural and compositional characteristics of minute structures. A large variety of systems may be studied with this instrument; some examples include very small metal particles , biological cells, light-emitting molecules and thin oil slicks on water surfaces. What unites all of these systems is their size scale -typically about one half of one thousandth the width of a human hair, and often even smaller than that. Conventional optical microscopes such as those in high school science labs cannot reveal spatial features of objects at such small size scales. This limitation is inherent to all commonly available optical systems which employ light and lenses for visualization and magnification of images. The smallest spatial feature which may be distinguished using these instruments is about one half the wavelength of visible light - approximately five to ten times larger than the systems we are interested in studying. However, if instead of a lens a minute aperture (even smaller than our smallest object!) is placed at very high proximity to the sample, imaging of much finer features is possible when the aperture is illuminated with visible light. Such a system will allow students and researchers at the University of Oregon and its affiliated Institutions to elucidate the characteristics of novel systems such as the smallest light emitting structures known to nature, fabricate ultra-compact electronic and optical devices, understand how chemical contaminants interact with their immediate environment, and study biological cell structure and functionality with unprecedented optical resolution.