Ph.D. Proposal Presentation by Ceji Fu
Friday, April 2, 2004
( Dr. Zhuomin Zhang, Chair)
"Near-Field and Localization Effects on Radiative Transfer in Multilayer Thin-Film Structures"
The proposed thesis aims at investigating by numerical simulation the near-field and localization effects on radiative transfer in a multilayer thin-film structure. Potential impacts are in microscale thermophotovoltaic devices, heated AFM cantilever tips for nano thermal processing, and controlled localized radiative absorption in multilayer structures. This thesis includes three relevant parts. The first part seeks to enhance the energy transmission of a multilayer structure using a novel metamaterial, the so-called left-handed material (LHM), by radiation tunneling with the excitation of surface waves for both s- and p-polarizations. Employing a LHM has a unique impact on the transmittance via evanescent waves. The second part studies the radiative heat transfer between two closely spaced semi-infinite media, at least one of which is silicon. The fluctuational electrodynamics approach is used. Attention will be paid to the effect of optical properties, which are functions of doping level and temperature, on the energy transfer (dominated by the near-field effect) between the two media. Understanding the near-field radiative transfer is important for applications such as the use of heated AFM tips for nano thermal processing. The third part focuses on the localization of electromagnetic fields, energy density, and absorption inside a multilayer system, consisting of two heterogeneous materials arranged in an alternate fashion. While the localization effect on the transmission and reflection has been well documented, very few previous studies dealt with the localization effect on the radiation absorption, which may be important for site dependent absorption of radiative energy and local heating effect.