Photonic Crystals, Wave Localization and Applications

我们建议阐明光子和声子晶体的新效应，着眼于实际应用。光子晶体的新颖之处在于它们能够以独特的方式相干地捕获光子，并且能够实现光与物质之间的强耦合。我们建议通过新型光学生物传感器来证明光子晶体在薄膜中高效太阳能收集和医学诊断方面的功效。我们建议开发薄膜光子晶体结构，用于下一代光伏电池的太阳光捕获和吸收。我们的工作将集中在计算设计和建模（包括波光学和电子学）以及与实验小组的密切合作。我们增强的光捕获和太阳吸收的基本物理原理是通过光子晶体在横向传播到薄膜表面的方向上的阳光与慢光模式的耦合。这对应于一个光谱范围，其中状态的光子密度相对于均匀材料的光子密度增强。这项研究的最终目标是实现一种薄的（10微米）硅太阳能电池，其功率转换效率超过30%。一个相关的课题是声波在声子晶体薄片中的俘获和吸收。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，达到隔音的目的。这包括声子带结构优化和声音从空气传递到薄声子晶体片的时域有限差分模拟。我们建议将用于医学诊断的实验室光子晶体生物传感器的研究扩展到适合低成本制造的现实3D架构。在光子带隙内，多种共振模式的相互作用促进了多种疾病标记物的光谱指纹和逻辑鉴别。我们的目标是与具有纳米柱光子晶体制造专业知识，微流体知识和具有生物相关分子的电介质表面功能化经验的领先实验小组密切合作。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。我们将研究由激子玻色凝聚中相互作用产生的量子多体相关的性质，如双激子费什巴赫共振。我们将阐明凝聚态辐射衰减时类激光光发射的性质。在吸引激子-极化子相互作用的情况下，我们将探索“薛定谔猫”和其他宏观量子叠加态的可能性，这些叠加态是在光子带隙的保护环境下实现的。

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.