NON-TECHNICAL ABSTRACT Unlike line-of-sight propagation in a translucent medium, light transport in an opaque medium is a seemingly random walk that is described by a diffusion process. Common to electronic, acoustic, as well as the electromagnetic waves, most of the incident wave is reflected, and only a small fraction is transmitted via a multitude of partial waves with a broad range of delay times. Counterintuitively, this behavior can be altered by exploiting wave interference. This award supports an experimental and theoretical efforts to investigate the degree, to which one can manipulate input waves in a chip-scale platform, to achieve near-100% transmission or avoid temporal spread of a short pulse. The collaborative program of an experimental group at Yale University and a theoretical group at Missouri University of Science & Technology will train graduate and undergraduate students to conduct interdisciplinary research across the evolving boundaries of multiple fields, including condensed matter physics, optics of complex media, nanotechnology, and computational physics. The cutting-edge research will be incorporated in the curriculum at both participating institutions. This project includes an extensive exchange program with visits by faculty and students, summer internships, design and assembly of optical demonstrations for undergraduate research projects and recruitment activities.
The concept of transmission eigenchannels has been a cornerstone of mesoscopic physics but it is also applicable to electromagnetic waves and acoustic waves. Despite of the essential role of the eigenchannels in mesoscopic transport and vast opportunities for optical/acoustic imaging applications, little is known about the intrinsic properties of individual transmission eigenchannels or the time-delay eigenchannels. This collaborative program supports a joint experimental and theoretical studies on the statistical properties of individual eigenchannels, such as their fluctuations and correlations, in a unique on-chip photonic platform that allows both selective coupling of light into a single eigenchannel and direct probe of its spatial structure inside the random medium. Compared to electronic systems, robustness of coherence effects for photons at room temperature makes optical systems ideal for the in-depth fundamental studies of coherent wave transport. The proposed work addresses long-standing questions in mesoscopic physics regarding the nature and statistical properties of individual transmission and time-delay eigenchannels and the roles they play in static and dynamic wave transport. A systematic comparison between the experimental and numerical results will provide key insights into how the eigenchannels are formed, what determines their properties, and whether it is possible to achieve simultaneously spatial and temporal control of wave transmission. The research program will produce a wide range of experimental and numerical data, which will pave the way for the mesoscopic physics community to develop and verify new theoretical models for coherent wave transport. In optics, the fundamental understanding of coherent propagation via eigenchannels will inform a broad range of practical applications, from laser surgery, photovoltaics, imaging in turbid media, to random laser and energy-efficient ambient lighting. The collaborative experimental-theoretical program will train graduate and undergraduate students to conduct interdisciplinary research across the evolving boundaries of multiple fields, including condensed matter physics, optics of complex media, nanotechnology, and computational physics. The cutting-edge research will be incorporated in the curriculum at both participating institutions. The two teams will join force in education outreach activities.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
