Band Flips and Bound States in Leaky-Mode Resonant Photonic Lattices

摘要标题：漏模共振光子晶格中的能带翻转和束缚态非技术部分光子晶格是具有不同折射率的材料的周期性结构。它类似于我们所熟悉的具有规则原子排列的晶格。光子晶格有效地反射、过滤和重定向入射光。超材料构成了一类新的光子晶格，其主要性能指标由一组亚波长粒子的特性控制。周期和非周期元表面和元聚合可以被塑造成以非常紧凑的格式提供复杂的功能，即使是单层的lms。无损介电介质尤其有希望用于高efp &amp；#64257；不熟悉的应用程序。因此，人们对探索超材料作为高性能光子器件（包括超透镜）的构建块非常感兴趣。以及新型全息图。在这里，我们提出在与光谱连续体中的渐近束缚态相连接的纳米光子共振系统中展示新的基本效应。在该项目下产生的新认识可能会导致控制光的创新方法。该项目为本科生和研究生提供了出色的分析和实验经验，从而支持下一代光子技术劳动力的发展。如果成功，该项目将带来具有巨大经济效益和社会价值的创新光学工程理念。本研究的目的是对漏模光子晶格中发生的能带翻转进行研究。它们与连续介质中非漏光子态或束缚态的联系引起了人们极大的兴趣。我们寻求对这些带翻转和相关束缚态转变的坚实物理理解，并建议用概念验证原型进行实验演示。这些元素将通过纳米压印光刻技术在纳米复合材料中形成周期性纳米结构，从而可以完美地控制空间调制、谐波含量和谱线宽度。我们研究了这些器件中共振相互作用的基本方面。详细的光谱特性包括波段结构将被测量。因此，我们将处理支持共振漏模的光子薄膜晶格。它们的特性包括多用途光谱、极化效应、具有强局域场的大量共振q因子和相位控制。如果晶格是对称的，则每个支持谐振模式的带结构都是独特的，支持漏边和非漏边。非泄漏边缘与连续体（BIC）中的束缚态或嵌入特征值相关联，目前具有很大的科学兴趣。通过点阵设计来控制漏带隙的宽度是可能的。当模态带闭合时，会产生准简并态？这种状态是值得注意的，因为它可以通过参数和材料的选择过渡到它，如图所示。这是可能的，动态抖动围绕这一点与带边过渡进入和走出BIC色散分支。有相关的调制和调谐的可能性。使用半解析和严格的数学方法，我们将描述相对于晶格谐波含量的带翻转和bic，因为这对带性质有很大的影响。我们将研究在各种模式带的漏模带翻转下bic生成的通带。此外，我们可以使用双共振结构与配对漏模器件实现带翻转。当器件彼此靠近时，共振带通过倏逝波耦合相互作用。该结构具有附加的干涉效应以及所述简单实施例的带跃迁和BIC特性。在束缚连续状态内外的电诱导耦合是可能的。这里提出的新带翻转概念在光子学的各个分支中具有很高的潜在影响，同时也有令人兴奋的新科学发现的可能性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Abstract title: Band Flips and Bound States in Leaky-Mode Resonant Photonic LatticesNontechnical partA photonic lattice is a periodic structure of materials with differing refractive indices. It is analogous to the familiar crystal lattice possessing a regular atomic arrangement. Photonic lattices effectively reflect, filter, and redirect incident light. Metamaterials constitute a new class of photonic lattices wherein principal performance metrics are controlled by the properties of a collection of subwavelength particles. Periodic and aperiodic metasurfaces and metagratings can be fashioned to provide complex functionality in extremely compact format even as single-layer films. Lossless dielectric media are particularly promising for high-efficiency applications. Thus, there is great interest in exploring metamaterials as building blocks for high-performance photonic devices including metalenses, perfect reflectors, and new types of holograms. Here, we propose to demonstrate new fundamental effects in nanophotonic resonance systems that are connected to asymptotic bound states in the spectral continuum. The new understanding generated under the project may lead to innovative ways to control light. The project provides excellent analytical and experimental experience for undergraduate and graduate students thus supporting the development of the next-generation workforce in photonics technology. If successful, the project will lead to innovative optical engineering ideas with substantial economic benefits and societal value. Technical partThe objective of this research is to conduct research into band flips found to occur in leaky-mode photonic lattices. Their connection with non-leaky photonic states or bound states in the continuum (BIC) is of great interest. We seek solid physical understanding of these band flips and associated bound-state transitions and propose to demonstrate them experimentally with proof-of-concept prototypes. These elements will be fashioned as periodic nanostructures in nanocomposites with nanoimprint lithography allowing perfect control of spatial modulation, harmonic content, and spectral linewidths. We investigate fundamental aspects of the resonance interactions in these devices. The detailed spectral properties including band structure will be measured. Thus, we will treat photonic thin-film lattices supporting resonant leaky modes. Their properties include versatile spectra, polarization effects, substantial resonant Q-factors with strong local fields, and phase control. The band structure is unique supporting a leaky edge and a non-leaky edge for each supported resonant mode if the lattice is symmetric. The non-leaky edge is associated with a bound state in the continuum (BIC), or embedded eigenvalue, currently of great scientific interest. It is possible to control the width of the leaky band gap by lattice design. As a modal band closes, there results a quasi-degenerate state?this state is remarkable as it is possible to transit to it by parametric and material choice as shown in this proposal. It is possible to dither dynamically around this point with band-edge transitions into and out of the BIC dispersion branch. There are associated modulation and tuning possibilities. Using semianalytical and rigorous mathematical methods, we will characterize band flips and BICs relative to lattice harmonic content as this has great effect on the band properties. We will study BIC-generated passbands under leaky-mode band flips for the various mode bands. Moreover, we can implement band flips using double resonance structures with paired leaky-mode devices. When the devices are close to each other, the resonance bands interact via evanescent-wave coupling. This configuration possesses additional interference effects along with the band-transition and BIC properties of the simpler embodiments. Electrically induced coupling in and out of the bound continuum states might be possible. The new band-flip concept proposed here is unexplored with high potential impact in various branches of photonics along with exciting possibilities for new scientific discoveries.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.