Statistics of Electromagnetic Propagation and Localization

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********NON-TECHNICAL ABSTRACT********The goal of the research is to obtain a comprehensive understanding of waves in disordered systems. Since all transport, be it electronic or acoustic, optical or microwave, is via the propagation of waves, this study will help unify diverse disciplines. As a result of the overlap of waves following different convoluted paths, waves can be localized and transport inhibited. The impact of wave localization determines the character of matter and energy migration. A statistical understanding of transport will be obtained by pulsed and steady-state microwave measurements of localization within and on the output surfaces of collections of realizations of random samples. Optical measurements in random stacks of material will also be carried out to explore the transformation of propagation from a one to a three dimensional problem as the wave is scattered by nonuniformity in the layer thickness. High school students, undergraduates, graduate students and a postdoctoral fellow involved in this research will learn to think out-of-the-box in their exploration of challenging fundamental problems with far-ranging applications to free-space and cellular communications, electronics, photonics, and medical imaging.******** TECHNICAL ABSTRACT********This project will explore fundamental aspects of electromagnetic propagation in random materials that will lead to a universal description of electronic and acoustic, as well as microwave and optical waves in multiply-scattering media. The affects of localization and absorption which are intertwined in steady-state experiments will be unscrambled in microwave measurements of the time evolution of the wave. The connection between statistics of propagation in single sample realizations and in a random ensemble will allow us to show the manner in which localization in the time domain arises from correlation of transmission with frequency shift. The spatial extent of the wave will also be measured inside a single-mode slotted waveguide containing randomly juxtaposed dielectric slabs. The field distribution will be analyzed as a sum of quasimodes plus an evanescent wave. Related optical measurements will be carried out in random layered media to explore the transformation of propagation from a one to a three dimensional problem as the wave is scattered by transverse inhomogeneity. High school students, undergraduates, graduate students and a postdoctoral fellow will be involved in collaborative fundamental research with applications to communications, electronics, photonics, and medical imaging.