CAREER: Digital plasmonics-based nano-tweezing and nano-imaging for nano-particles

职业：基于数字等离子体的纳米镊子和纳米颗粒纳米成像

基本信息

批准号：
1552642
负责人：
Nathan Lindquist
金额：
$ 50万
依托单位：
Bethel University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-01 至 2022-01-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1552642&HistoricalAwards=false
关键词：
CAREER Digital plasmonics based nano

项目摘要

Light is an extremely powerful tool to probe, image, and even manipulate small objects. Unfortunately, since light is a wave it is limited by diffraction, or the tendency of all waves to spread out. As a result very small nano-sized objects like the basic components of cells, single molecules, viruses, and nano-devices are too small to beindividually probed, manipulated, and imaged directly with light. However, the field of 'plasmonics' allows manipulating light with sub-wavelength precision at the surface of metallic nano-structures. Plasmons can squeeze their optical energy into ~10 nanometer spaces, an ideal size for directly interacting with nano-sized objects that are on or near these metallic surfaces. Precise manipulation of plasmons requires careful illumination with light, and extremely sensitive optical recording equipment. PI has the capability of digital and computational techniques to both: (1) excite plasmons to directly manipulate nano-objects under computer control; and (2) carefully record the behavior of plasmons to directly image the shape, size, and thickness of nano-objects. These digital techniques will open up new opportunities for scientists under precise computer control to directly study, probe, image, manipulate, and interact with nano-sized objects such as DNA, protein molecules, quantum dots, viruses, or nanoparticles. Furthermore, since this research is being performed exclusively with undergraduate students, it promises to inspire, motivate, and train many new young scientists and engineers.The emergence of digital techniques that explicitly model the propagation of light has revolutionized optical imaging and optical tweezing through 'digital holographic microscopy' and 'computer generated holography'. These techniques offer many advantages over conventional optics such as: (1) imaging or generating the full complex wave; (2) fast beam scanning with no moving parts; (3) dynamic manipulation of trapped objects; (4) eliminating aberrations and imaging through scattering media; and (5) freedom to choose any imaging modality, e.g. phase vs. amplitude contrast. Unfortunately, these powerful digital techniques have not yet been fully realized in near-field optics, and in particular, with plasmons. Indeed, plasmonic nano-imaging and nano-tweezing have recently generated immense interest to trap, probe, manipulate, and image nano-sized objects such as viruses, nanoparticles, and individual molecules. Therefore, introducing powerful digital optical techniques into the near-field promises to have a large impact. Specifically, a spatial light modulator will be used to generate computer-controlled, tightly focused plasmons for nano-tweezing and high-spatial frequency plasmonic fields for super-resolution imaging. The phase of the plasmon waves will also be imaged by designing interferometers directly into the nano-metallic substrates or by recording a digital hologram of the reflected or transmitted light. These two techniques will enable significant new capabilities such as: (1) super-resolution, high-speed plasmonic phase-contrast imaging to image the thickness of biological structures; (2) trapping and real-time manipulation of nano-metric objects for nanofabrication or sorting; and (3) optical probing of trapped nano-objects for spectroscopic characterization of single molecules.

光是探测、成像甚至操纵小物体的极其强大的工具。不幸的是，由于光是一种波，它受到衍射或所有波扩散的趋势的限制。因此，非常小的纳米尺寸物体，如细胞的基本成分、单分子、病毒和纳米器件太小，无法直接用光单独探测、操作和成像。然而，“等离激元”领域允许在金属纳米结构表面以亚波长精度操纵光。等离子体激元可以将其光能压缩到约 10 纳米的空间中，这是与这些金属表面上或附近的纳米尺寸物体直接相互作用的理想尺寸。等离子体激元的精确操纵需要仔细的光照射和极其灵敏的光学记录设备。 PI具有数字和计算技术的能力，可以：（1）激发等离子激元，在计算机控制下直接操纵纳米物体；（2）仔细记录等离子体激元的行为，以直接对纳米物体的形状、尺寸和厚度进行成像。这些数字技术将为科学家在精确的计算机控制下直接研究、探测、成像、操纵纳米级物体（如 DNA、蛋白质分子、量子点、病毒或纳米粒子）并与之交互提供新的机会。此外，由于这项研究仅针对本科生进行，因此它有望激励、激励和培训许多新的年轻科学家和工程师。明确模拟光传播的数字技术的出现，通过“数字全息显微镜”和“计算机生成全息术”。与传统光学器件相比，这些技术具有许多优点，例如：（1）成像或生成完整的复杂波； (2) 快速光束扫描，无移动部件； (3)动态操纵被困物体； (4)消除像差并通过散射介质成像； (5) 自由选择任何成像方式，例如相位与幅度对比。不幸的是，这些强大的数字技术尚未在近场光学中完全实现，特别是等离子体激元。事实上，等离子体纳米成像和纳米镊子最近引起了人们对捕获、探测、操纵和成像纳米尺寸物体（如病毒、纳米颗粒和单个分子）的巨大兴趣。因此，将强大的数字光学技术引入近场有望产生巨大的影响。具体来说，空间光调制器将用于生成计算机控制的、紧密聚焦的等离子体激元，用于纳米镊子和高空间频率等离子体场，用于超分辨率成像。通过将干涉仪直接设计到纳米金属基底中或通过记录反射或透射光的数字全息图，也可以对等离激元波的相位进行成像。这两项技术将实现重要的新功能，例如：（1）超分辨率、高速等离子体相衬成像，以对生物结构的厚度进行成像； (2) 捕获和实时操纵纳米物体以进行纳米加工或分类； (3) 对捕获的纳米物体进行光学探测，以进行单分子的光谱表征。