Collaborative Research: Mesoscopic Transport and Localization in Active Random Media

* 非技术摘要 * 光散射解释了我们日常生活中的许多现象，例如，天空是蓝色的，牛奶是白色的。如果散射很强，光就会停止，因为光的粒子-光子-会“迷失在丛林中”。这种现象被称为局域化，最早是在电子的凝聚态物理学中引入的。与电子不同，光子的数量可以成倍增加。当一个光子最终从“丛林”中出现时，很难分辨它是输入光子还是在原始光子随机行走过程中产生的另一个光子。该项目的目标是通过进行数值模拟和实验跟踪“丛林”中的光子来了解光局部化和放大之间的相互作用。从拟议的工作中获得的物理洞察力可能会导致新的光学技术的发展，非侵入性的实时表征的生物组织中的光散射是强烈的。此外，该项目的结果将有助于理解随机激光器-一种由随机介质制成的非常规激光器。这项合作研究计划的跨学科性质将影响凝聚态物理和光学。参与该计划的研究生和本科生将接受广泛的培训。拟议的教育活动包括课程编制和教育推广，这将丰富参与机构的研究和教育环境。技术摘要 * 在电子系统中没有对应部分的情况下，光子的相干放大为介观输运和安德森局域化的基础研究增加了新的维度。本计画的主要目标是了解随机介电介质中相干放大对介观波输运的影响。该合作研究计划结合了实验和数值研究光传输和本地化的二维随机系统的增益或吸收。近场扫描光学显微镜将被用来研究局部场和强度的统计特性，包括空间和光谱相关性，场和强度分布和矩。这些研究将提供物理洞察本地化和放大之间的复杂的相互作用，途中制定安德森本地化的标准在积极的随机系统。实验组和理论组之间的密切合作对拟议研究计划的成功至关重要。参与这个跨学科项目的研究生和本科生将接受凝聚态物理和光学方面的广泛培训。拟议的教育活动包括课程编制和教育推广，这将丰富参与机构的研究和教育环境。

****NON-TECHNICAL ABSTRACT****Light scattering accounts for many phenomena in our daily life, e.g., the sky is blue, milk is white. If the scattering is strong, light can be brought to a standstill as the particles of light - photons - get "lost in a jungle". This phenomenon, called localization, was first introduced in condensed matter physics for electrons. Unlike electrons, the number of photons can be multiplied. When a photon eventually emerges from the "jungle", it is hard to tell whether it is the input one or another one created during the random walk of the original photon. The goal of the project is to understand the interplay between light localization and amplification by performing numerical simulations and experimentally tracking the photons in the "jungle". The physical insight obtained from the proposed work may lead to the development of new optical techniques for non-invasive real-time characterization of biological tissues in which light scattering is strong. Also, the outcome of the project will be instrumental in understanding the random laser - an unconventional laser made of random medium. The interdisciplinary nature of this collaborative research program will impact both condensed matter physics and optics. The graduate and undergraduate students involved in this program will receive extensive training. The proposed education activities include the curriculum development and educational outreach, which will enrich the research and education environments at the participating institutions.**** TECHNICAL ABSTRACT****Without a counter-part in electronic systems, coherent amplification of photons adds a new dimension to the fundamental study of mesoscopic transport and Anderson localization. The main goal of this project is to understand the effects of coherent amplification on mesoscopic wave transport in random dielectric media. The collaborative research program combines experimental and numerical studies on light transport and localization in two-dimensional random systems with gain or absorption. Near-field scanning optical microscopy will be employed to investigate the statistical properties of local fields and intensities, including the spatial and spectral correlations, the field and intensity distributions and moments. These studies will provide physical insight into the intricate interplay between localization and amplification, enroute to formulating the criterion of Anderson localization in active random systems. The close collaboration between an experimental and theoretical group is crucial to the success of the proposed research program. The graduate students and undergraduate students involved in this interdisciplinary program will receive extensive training in both condensed matter physics and optics. The proposed education activities include the curriculum development and educational outreach, which will enrich the research and education environments at the participating institutions.