Wave Engineering in Time Modulated, Nonlinear, and Anisotropic Metamaterials
type: CreativeWork
description: 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 …
abstract: 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 …
author: Mekawy, Ahmed
keywords: parametric amplification, electrically small antennas, second harmonic generation, phase tri-stability, hyperbolic metasurface, Electrical and Electronics, Electromagnetics and Photonics
date published: 2022-01-01T08:00:00Z
date modified: 2026-07-24T01:57:53Z
provider: City University of New York - City College
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: City University of New York - City College