New materials and structures for terahertz plasmonic applications

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Title New materials and structures for terahertz plasmonic applications
Publication Type dissertation
School or College College of Engineering
Department Electrical & Computer Engineering
Author Liu, Shuchang
Date 2016
Description This dissertation describes our work on design, fabrication and characterization of plasmonic metamaterials and tapered structures, with primary focus on their applications at terahertz (THz) frequencies. The phenomena associated with these structures rely on surface plasmon polaritons (SPPs), which may allow for high field enhancement and tight field confinement. We have investigated the underlying mechanisms of these structures and used that knowledge to develop unique and practical applications. We first studied two-dimensional periodic and random lattices based on aperture arrays, and modified the model to describe the effective dielectric response of the perforated metallic medium. Using two layers of the perforated stainless steel films, we demonstrated the emergence of an additional resonance and reproduced the transmission spectra using the effective dielectric model of the single-layer medium. Also, we improved the filtering performance of the multilayer periodic aperture arrays by adjusting the relative distance and angle between the layers, and demonstrated its application as a high quality bandpass filter. Then, we examined the transmission properties of graphite and carbon nanotube (CNT) films, and then the same films perforated with periodically distributed aperture arrays. The extracted dielectric constants of the graphite and CNT films demonstrate their availability for THz surface plasmonic devices. Moreover, we developed a narrow band/multiband THz detector in which the photoconductive antenna was surrounded by periodically corrugated gratings. This detector not only enhanced the sensitivity of detection at the specific frequencies, but also efficiently collected the radiation within the structure area, which obviated the need for a substrate lens. Finally, we improved the concentration properties of conically tapered apertures. Based on the optimal taper angle we determined, we introduced various modifications to the individual tapered aperture, e.g., to form an array and insert a gap spacing, and further enhanced the concentration capabilities and realized complete broadband transmission. Based on these studies and results, we are currently extending our work towards development of more reconfigurable and active devices that could enrich the available pool of THz and optical devices. Furthermore, such THz devices have great promise for the development of THz systems level applications and even a THz-based world in the future.
Type Text
Publisher University of Utah
Subject metamaterials; periodic structures; surface plasmon polaritons; tapered structures; terahertz
Dissertation Name Doctor of Philosophy
Language eng
Rights Management ©Shuchang Liu
Format application/pdf
Format Medium application/pdf
Format Extent 27,188 bytes
Identifier etd3/id/4092
ARK ark:/87278/s6ck1nsb
Setname ir_etd
ID 197642
Reference URL https://collections.lib.utah.edu/ark:/87278/s6ck1nsb
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