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City University of New York - City College

Wave Engineering in Time Modulated, Nonlinear, and Anisotropic Metamaterials

Abstract

dc:description.abstract

<p>Leveraging wave matter interactions is central to a myriad of electromagnetic wave-based applications. During the past decades, research on extreme wave manipulation has been revolutionized by artificially engineered materials (metamaterials) and by adding new aspects to the wave-matter interactions that showed intriguing results inaccessible in conventional linear, time invariant (LTI), passive and isotropic media. In this work, I will explore, numerically and experimentally, the possibility of realizing devices that perform beyond or close to their fundamental LTI limitations by adding periodic modulation, nonlinearity, and gain. I will demonstrate these concepts at radio frequencies (RF) and at optical frequencies. Specifically, at RF I will show that small periodic temporal modulation of nonlinear matching network can enhance the radiation of electrically small antennas by boosting unbalanced energy exchange between the wave and the modulating pump. I will show how large modulation ratios can be exploited to build novel compact phase conjugator, time reversal devices. In harnessing the role of nonlinearity, I will show the experimental demonstration of a single unit cell of parametric frequency divider-by-3 that enable phase tri-stability– an important feature needed to realize computational platform for combinatorial optimization problems. Extending RF modulation schemes to optical frequencies is hindered by current technologies, which only allow small modulation ratios and speeds. I will demonstrate how weak optical nonlinearities can replace temporal modulation at RF to efficiently achieve similar effects, for instance realizing nonlinearity-based nonreciprocity, in which the wave itself modulates the medium, overcoming speed limitations. To further increase the efficiency, I will show how nonlinear generation and wave mixing can be obtained in thin 2D periodic structures based on multi-quantum-wells, and in parallel I demonstrate how to enhance nonlinearity from 2D materials, as well as show the possibility to engineer the dispersion of hyperbolic surface wave propagation on judiciously designed metasurfaces that leverage enhanced wave-matter interactions, opening new avenues for compact imaging and sensing devices.</p> <p>TRANSLATE with x English <a>Arabic</a> <a>Hebrew</a> <a>Polish</a> <a>Bulgarian</a> <a>Hindi</a> <a>Portuguese</a> <a>Catalan</a> <a>Hmong Daw</a> <a>Romanian</a> <a>Chinese Simplified</a> <a>Hungarian</a> <a>Russian</a> <a>Chinese Traditional</a> <a>Indonesian</a> <a>Slovak</a> <a>Czech</a> <a>Italian</a> <a>Slovenian</a> <a>Danish</a> <a>Japanese</a> <a>Spanish</a> <a>Dutch</a> <a>Klingon</a> <a>Swedish</a> <a>English</a> <a>Korean</a> <a>Thai</a> <a>Estonian</a> <a>Latvian</a> <a>Turkish</a> <a>Finnish</a> <a>Lithuanian</a> <a>Ukrainian</a> <a>French</a> <a>Malay</a> <a>Urdu</a> <a>German</a> <a>Maltese</a> <a>Vietnamese</a> <a>Greek</a> <a>Norwegian</a> <a>Welsh</a> <a>Haitian Creole</a> <a>Persian</a> TRANSLATE with COPY THE URL BELOW <a id="x-x-ShareBack" title="Back To Translation"> Back</a> EMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: <a href="http://www.bing.com/widget/translator" target="_blank">Bing Webmaster Portal</a> <a title="Back To Translation">Back</a></p>

Degree

thesis:*
Name thesis:degree_name
Doctor of Philosophy (Ph.D.)
Level thesis:degree_level
Dissertation
Discipline thesis:degree_discipline
Engineering
Year dc:date.available
2022

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Mekawy, Ahmed
Contributors dc:contributor
  • Andrea Alu

Subjects

dc:subject × 7

Identifiers

dc:identifier.*
Repository record dc:identifier
https://academicworks.cuny.edu/cc_etds_theses/1060
OAI identifier oai:identifier
oai:academicworks.cuny.edu:cc_etds_theses-2076

Chain of custody

source
Harvested from
City University of New York - City College
Base URL
academicworks.cuny.edu/do/oai/
Last updated
2026-07-24
Source record
OAI-PMH GetRecord
citation

Mekawy, Ahmed. Wave Engineering in Time Modulated, Nonlinear, and Anisotropic Metamaterials. Dissertation thesis, 2022. https://academicworks.cuny.edu/cc_etds_theses/1060