New Perspectives on Wave Propagation in Random Media

随机介质中波传播的新视角

• 批准号: 1207446
• 负责人: Azriel Genack
• 金额: $ 37.5万
• 依托单位: CUNY Queens College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-15 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207446&HistoricalAwards=false
• 关键词: New; Perspectives; Wave; Propagation; Random

****Technical Abstract****Measurements of the spectrum of the microwave field pattern at the output surface and on a line along the length of disordered samples generated by a source moved to points on a grid over the sample's input surface will provide a comprehensive picture of waves transport. Related measurements will be carried out using laser light and a spatial light modulator and CCD camera. The analyses of these measurements will be supplemented with finite difference time domain numerical simulations. This research will advance four distinct perspectives on wave transport and the relationships between them: the spatial structure of (1) modes and (2) transmission eigenchannels, as well as the variation with position of (3) the local diffusion coefficient, and (4) the field speckle pattern for both diffusive and localized waves. Wave statistics determined in single samples will guide applications to focusing, imaging, and enhanced transmission in random systems. The joint experimental, theoretical and numerical study of fundamental and applied aspects of propagation using microwave radiation and light will provide and ideal learning experience for the undergraduate, graduate, and high school students and the postdoctoral fellow involved in this research. The work will strengthen the photonics initiative at CUNY and foster photonic technological in the New York City area. ****Non-Technical Abstract****The manner in which waves propagate in random media affects our ability to communicate and image and to create electronic and photonics devices. The study of waves in multiply-scattering systems is all the more challenging because of the twin difficulties of probing the interior of scattering samples and measuring the full scattered field. In this project, we will measure the wave pattern generated by sources of microwave radiation and light at various positions on the output of disordered samples as well as microwave radiation in the interior of such samples. This full set of measurements will allow us to determine the natural modes of oscillation as well as the specific transmission channels for waves in each random sample as well as the position dependent flux and intensity of the wave and the nature of fluctuations of intensity throughout the sample. The work will enable optimal focusing through and within random systems and will yield nearly complete transmission even in ordinarily opaque systems. The use of both microwave and laser measurements for challenging fundamental and applied problems will advance the education and careers of graduate students, undergraduates, high school students and a postdoctoral fellow involved in the research. The success of this work will strengthen the CUNY Photonic Center established to enhance the technological base of the New York City metropolitan area.

* 技术摘要 * 测量输出表面和沿无序样品长度沿着的微波场图案的频谱，该无序样品由移动到样品输入表面上的网格上的点的源产生，将提供波传输的全面图片。相关测量将使用激光和空间光调制器和CCD相机进行。这些测量的分析将补充有限差分时域数值模拟。这项研究将提出四个不同的角度对波的传输和它们之间的关系：（1）模式和（2）传输本征通道的空间结构，以及（3）局部扩散系数的位置变化，（4）场散斑图案的扩散和局域波。在单个样品中确定的波统计将指导应用于随机系统中的聚焦，成像和增强传输。使用微波辐射和光传播的基础和应用方面的联合实验，理论和数值研究将为本科生，研究生和高中生以及参与这项研究的博士后提供理想的学习经验。这项工作将加强纽约市立大学的光子学倡议，并促进纽约市地区的光子技术。* 非技术摘要 * 波在随机介质中传播的方式影响我们通信和成像以及创建电子和光子器件的能力。多重散射系统中的波的研究由于散射样品内部探测和全散射场测量的双重困难而更具挑战性。在这个项目中，我们将测量由微波辐射源和光源在无序样品的输出上的不同位置产生的波型，以及这些样品内部的微波辐射。这一整套测量将使我们能够确定振荡的自然模式以及每个随机样品中波的特定传输通道，以及波的位置相关通量和强度以及整个样品中强度波动的性质。这项工作将使最佳聚焦通过和随机系统内，并将产生几乎完全传输，即使在通常不透明的系统。使用微波和激光测量来解决具有挑战性的基础和应用问题，将促进研究生、本科生、高中生和参与研究的博士后的教育和职业发展。这项工作的成功将加强为加强纽约市大都市区的技术基础而建立的纽约市立大学光子中心。