Mesoscopic wave physics and complex materials

复杂介质中的波表现出显著的性质，其中许多是由强烈的多次散射引起的，并继续挑战我们对波动物理的基本理解。 这门学科是许多科学和工程学科的基础，这些学科依赖于用于成像和材料表征的基于波的技术。 波通过复杂介质的传输也是我们繁荣的基础，因为它影响了我们对复杂结构的成像能力（例如，混凝土桥梁和技术装置的缺陷），并有效地前景和提取自然资源。 我的研究计划的目标是建立在我的实验室的最新进展，以解决复杂的强散射材料的波动物理学中最重要的未解决的问题，并开发和使用新技术，基于我们的波散射知识，探测它们的结构和动力学。 为了实现这些目标，我和我的学生将使用我们开创的技术进行最先进的超声波实验，这些技术被国际公认为解决该领域许多关键挑战的最强大方法。 我们的独特优势源于我们能够记录有关波传输的完整信息，研究具有精确确定结构的材料的可行性，所涉及的长度和时间的方便范围，以及使用新的理论模型解释我们的数据的可能性。 我们将研究的有趣的波现象的例子包括安德森局域化（由于无序导致的波的最终捕获）和由于负折射导致的人工结构材料（声子晶体和超材料）的显着聚焦特性。 我们还将为复杂介质开发新的动态成像方法（传统成像技术失败），从而为材料表征和过程控制带来新的超声光谱。 我们将使用这些技术来研究多孔和颗粒材料，泡沫，气泡凝胶和充气食品生物材料。 波行为的普遍性意味着我们研究的影响可能远远超出超声波，促进其他研究领域的进步。

Waves in complex media exhibit remarkable properties, many of which result from strong multiple scattering and which continue to challenge our basic understanding of wave physics. This subject underpins many scientific and engineering disciplines that rely on wave-based techniques for imaging and materials characterization. The transport of waves through complex media is also fundamental to our prosperity, as it affects, for example, our ability to image complex structures (e.g., defects in concrete bridges and technological devices) and to effectively prospect for and extract natural resources. The goals of my research program are to build on recent progress in my laboratory to address the most important unresolved questions in the wave physics of complex strongly scattering materials, and to develop and use new techniques, based on our knowledge of wave scattering, to probe their structure and dynamics. To achieve these objectives, my students and I will perform state-of-the-art ultrasonic experiments, using techniques that we have pioneered and that are recognized internationally as some of the most powerful approaches to addressing many key challenges in the field. Our unique advantage stems from our ability to record complete information about wave transport, the feasibility of studying materials with precisely determined structures, the convenient range of lengths and times involved, and the possibility of interpreting our data using new theoretical models. Examples of intriguing wave phenomena that we will investigate include Anderson localization (the ultimate trapping of waves due to disorder) and the remarkable focusing properties of artificially structured materials (phononic crystals and metamaterials) due to negative refraction. We will also develop new dynamic imaging methods for complex media (in which traditional imaging techniques fail), leading to new ultrasonic spectroscopies for materials characterization and process control. We will use these techniques to study porous and granular materials, foams, bubbly gels, and aerated food biomaterials. The universality of wave behaviours implies that the impact of our research may extend well beyond ultrasonics, facilitating advances in other fields of research.