Photonic Crystals, Wave Localization and Applications

我们建议从实际应用的角度来阐明光子晶体和声子晶体中的新效应。光子晶体的新颖性源于它们以独特的方式相干捕获光子的能力，以及它们能够在光和物质之间实现强烈的耦合。我们建议通过新型光学生物传感器来展示光子晶体在薄膜中高效收集太阳能和用于医疗诊断的功效。我们建议开发用于下一代光伏中太阳能光捕获和吸收的薄膜光子晶体结构。我们的工作将集中在计算设计和建模(包括波动光学和电子学)以及与实验小组的密切合作上。我们增强的光捕获和太阳吸收的基本物理是通过将太阳光耦合到光子晶体的慢光模式，这些模式在横跨薄膜表面的方向上传播。这对应于光子态密度相对于均匀材料的光子态密度增强的光谱范围。这项研究的最终目的是实现一种功率转换效率在30%以上的薄(10微米)硅太阳电池。与此相关的一个主题是声子晶体薄片中的声波捕获和吸收。我们建议研究平行界面折射和慢声模式在适当设计的周期性调制弹性材料中的作用，以实现宽带吸声以达到隔音的目的。这涉及到声子能带结构的优化和声音从空气进入薄声子晶体薄片的有限差分时域模拟。我们建议将用于医疗诊断的光子晶体实验室生物传感器的研究扩展到适合低成本制造的逼真3D结构。通过光子带隙内多个共振模式的相互作用，促进了多个疾病标志物的光谱指纹和逻辑识别。我们的目标是与领先的实验小组密切合作，这些小组拥有纳米柱光子晶体制造方面的专业知识、微流体方面的知识以及使用生物相关分子对介电表面进行功能化处理的经验。我们建议设计和表征能够在室温下实现激子-极化子相干和长寿命平衡玻色-爱因斯坦凝聚的新材料。我们将研究激子玻色凝聚体中相互作用产生的量子多体关联的性质，如双激子Feshbach共振。我们将阐明凝聚体以辐射方式衰变时类激光发光的本质。在激子-偏振子相互作用具有吸引力的情况下，我们将探索在光子带隙的保护环境下可能出现的薛定谔猫和其他宏观量子叠加态。

We propose to elucidate novel effects in photonic and phononic crystals with an eye to practical applications. The novelty of photonic crystals arises from their ability to coherently trap photons in unique ways and their enabling of strong coupling between light and matter.  We propose to demonstrate the efficacy of photonic crystals for high-efficiency solar energy harvesting in thin-films and for medical diagnostics through novel optical bio-sensors. We propose to develop thin-film photonic crystal architectures for solar light trapping and absorption in next generation photovoltaics. Our effort will focus on the computational design and modeling (both wave optics and electronics) and close collaboration with experimental groups. The underlying physics of our enhanced light trapping and solar absorption is through the coupling of sunlight to slow-light modes of the photonic crystal that propagate in directions transverse to the thin-film surface. This corresponds to a spectral range where the photonic density of states is enhanced relative to that of a homogeneous material. The ultimate aim of this research is the realization of a thin (10 micron) silicon solar cell with power conversion efficiency above 30%.  A related topic is acoustic wave trapping and absorption in thin phononic crystals sheets. We propose to study the role of parallel-to-interface refraction and slow-sound modes in suitably designed, periodically-modulated, elastic materials to achieve broad-band sound absorption for the purpose of sound-proofing. This involves phononic band structure optimization and finite-difference time-domain simulations of sound passing from air into thin phononic crystal sheets. We propose to extend our study of lab-in-a-photonic-crystal biosensors for medical diagnostics to realistic 3D architectures amenable to low-cost fabrication. The spectral fingerprinting and logical discrimination of multiple disease-markers is facilitated by the interaction of multiple resonance modes within a photonic band gap. Our aim is to work closely with leading experimental groups with expertise in fabrication of nano-pillar photonic crystals, knowledge in micro-fluidics and experience in functionalizing dielectric surfaces with biologically relevant molecules. We propose to design and characterize new materials capable of realizing exciton-polariton coherence and long-lifetime, equilibrium Bose-Einstein condensation at room temperature.  We will study the nature of quantum many-body correlations resulting from interactions in the excitonic Bose condensate such as bi-exciton Feshbach resonances. We will elucidate the nature of laser-like light emission as the condensate decays radiatively. In the case of attractive exciton-polariton interactions, we will explore the possibility of "Schrodinger Cat" and other macroscopic quantum superposition states made possible by the protective environment of the photonic band gap.