Nanoprobes for nano-femto optics

智力优势：本研究的目标是开发一种非线性纳米探针，用于超快光学近场的纳米飞米尺度时空表征。所提出的纳米探针由附着在纳米线上的非线性纳米粒子组成，纳米线又附着在硅纤维锥度上。纳米粒子的非线性特性可以通过自相关或频率分辨的光学门控测量来实现时间表征，而纳米尺度的空间分辨率则可以通过近场扫描来实现。我们将开发双光子荧光和二次谐波纳米探针，开发和优化基于纳米探针的时空表征技术，并研究所提出的基于纳米探针的方法的精度。利用所提出的非线性纳米探针的独特功能，我们还计划研究它们在探测几个有趣的超快光学近场中的应用。广泛的影响：所提出的纳米探针可以显著推进纳米超快技术的发展，这反过来又可以在许多科学学科中产生深远的影响，它们在其中发挥着核心作用。该非线性纳米探针具有提供纳米尺度时空映射的独特能力，具有广泛的应用前景。关于超快状态下光-物质相互作用的基本问题，复杂纳米结构的超快动力学，以及纳米等离子体结构中的非线性光学，都可以从纳米探针的发展中受益。因此，所提出的研究将对非线性光学显微镜和纳米光子学等领域产生相当大的影响。建议的研究是高度跨学科的，也可以为学生提供良好的教育机会。

Intellectual merit: The goal of the proposed research is to develop a nonlinear nanoprobe for nano-femto scale spatiotemporal characterization of ultrafast optical near fields. The proposed nanoprobe consists of a nonlinear nanoparticle attached to a nanowire, which is in turn attached to a silica fiber taper. The nonlinearity of the nanoparticle enables temporal characterization through autocorrelation or frequency resolved optical gating measurements while the nanoscale spatial resolution is achieved through near field scanning of the nonlinear nanoparticle. We will develop two-photon fluorescent and second harmonic nanoprobes, develop and optimize nanoprobe based spatiotemporal characterization technique, and investigate the precision of the proposed nanoprobe based method. With the unique capabilities of the proposed nonlinear nanoprobes, we also plan to investigate their applications to probing several interesting ultrafast optical near fields.Broad impact: The proposed nanoprobe can significantly advance the state of the art of nano & ultrafast technology, which can in turn create far-reaching impacts in many scientific disciplines in which they play a central role. With its unique capability in providing nano-femto scale spatiotemporal mappings, the proposed nonlinear nanoprobe can find many important applications. Fundamental questions with regard to light-matter interaction in the ultrafast regime, ultrafast dynamics of complex nanostructures, and nonlinear optics in nanoscale plasmonic structures, can all benefit from the development of the proposed nanoprobe. As a result, the proposed research can have considerable impact on areas such as nonlinear optical microscopy and nanophotonics. The proposed research is highly interdisciplinary and can also provide excellent education opportunities for students.