Materials World Network: Nonlinear Optical Metamaterials-Fabrication, Characterization, Theory

该项目研究了一类新的人工非线性纳米光子材料，它利用了研究人员将纳米制造与材料固有特性结合起来的能力来定制这些超材料的光学响应。全面理解和实验实现超材料非线性光学特性的主要挑战是，超材料的表面和体非线性光学理论尚未发展起来，而且还缺乏一种实际的方法来制作和测试这种理论。此次合作的核心理由是，它将伦敦大学学院的一个强大的英国团队在非线性光学和聚焦离子制造能力方面的理论能力与哥伦比亚大学的一个美国团队在集成和等离子体制造，光学测试和材料制备方面的证明记录相匹配。与布鲁克海文国家实验室（BNL）纳米中心以及与伦敦纳米技术中心的相互作用对制造也很重要。感兴趣的材料包括铁电体和等离子体金属中的周期性纳米结构。研究了几种纳米光子结构，包括光子晶体，负折射率超材料，以及利用薄膜中的电光效应对这些材料进行调谐。新的理论方面，包括非线性效应的等离子体散射和等离子体增强光学吸收薄膜。这里进行的研究有几个领域具有广泛的影响。首先，它促进了人工非线性超材料基础材料科学的跨学科研究，包括制造和生长，材料物理，光学物理和理论。其次，它使位于美国和英国的两家拥有悠久互动历史、专业知识和能力互补的集团得以合作。这项工作为研究生和本科生提供了在国际环境中合作和旅行的机会。第三，该项目有具体的计划和程序，通过对哥伦比亚大学本科生的四次外展讲座和在英国伦敦大学学院的一次外展讲座，寻求招募不同的学生合作者。它还使学生能够积极参与哥伦比亚大学的本科生研究机会计划（UROP）。第四，该项目使学生能够通过长期访问和短途旅行与美国主要国家实验室，即布鲁克海文的新纳米中心以及伦敦纳米技术中心进行合作。

This project conducts research into a new class of artificial nonlinear nanophotonic materials, which makes use of the investigators ability to use nanofabrication in conjunction with intrinsic materials properties to tailor the optical response of those metamaterials. The main challenges towards a comprehensive understanding and experimental realization of nonlinear optical properties of metamaterials are that a theory of surface and bulk nonlinear optics of metamaterials is yet to be developed, and a practical means to fabricate and test such a theory is missing as well. The central rationale for this collaboration is that it matches a strong UK group at University College London with demonstrated theoretical capabilities in nonlinear optics and focused-ion-based fabrication capabilities, with a US group at Columbia University with a demonstrated record of integrated and plasmonic fabrication, optical testing, and materials preparation. Interactions with the Brookhaven National Laboratory (BNL) Nanocenter as well as that with the London Centre for Nanotechnology are also important for fabrication. The materials of interest include periodic nanostructures in ferroelectrics and in plasmonic metals. Several nanophotonic structures are examined, including photonic crystals, negative index metamaterials, and tuning of these materials using electrooptical effects in thin membranes. New theoretical aspects are also examined, including nonlinear effects in plasmonic scattering and plasmonic enhancement of optical absorption in thin films.The research undertaken here has several areas of broad impact. First, it fosters an interdisciplinary examination of the fundamental materials science of artificial nonlinear metamaterials, including fabrication and growth, materials physics, optical physics, and theory. Second, it enables two groups in the US and the UK, with a strong history of interactions and complementary expertise and capabilities, to collaborate. This work involves the opportunity for both graduate and undergraduate students to collaborate and travel in an international setting. Third, the project has concrete plans and procedures to seek out recruitment of diverse student collaborators via four outreach talks to undergraduates at Columbia University and one outreach talk at University College London, UK. It also enables active participation of students in the undergraduate research opportunities program (UROP) at Columbia. Fourth, the project enables students to collaborate via extended visits and shorter trips with a major US National Laboratory, i.e. Brookhaven, in their new Nanocenter, as well as the London Centre for Nanotechnology.