Ultra-fast-all-optical switching based on graphene

• Main Author: Loganathan, Vishnu
• Other Authors: Luo Yu
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/157508
• Institution: Nanyang Technological University

Electromagnetic metamaterials are man-made materials made up of structures with electromagnetic properties that are designed to provide a range of response that is nearly impossible to obtain in naturally occurring materials or composites. Negative index of refraction (when the magnetic and electric responses are both negative), "perfect" (sub-wavelength) lensing, and electromagnetic "invisibility" cloaks are just several of the amazing uses of metamaterials.[1] In this project, we will apply graphene to designing ultrafast optical switch. Graphene, which was awarded Nobel Prize in Physics in 2010, is a new class of material made of one-atom thin planar sheet of carbon atoms. It has shown large intrinsic nonlinearity, but its direct photonic applications suffer from its relatively inefficient interaction with light. The hybridization of Fano resonance nanostructures with graphene can therefore strengthen light-graphene interactions drastically and provide larger effective susceptibilities than the intrinsic material susceptibility. Using both theoretical and experimental study, our goal is to design fast, cost-effective, and energy-efficient active optical elements based on graphene-Fano hybrid systems, with exceptionally strong ultrafast nonlinearities for application to all-optical switching, which is anticipated to become a key technology to meet society's request for future communication. There are two main parts to this project, the first part will discuss the fundamental concepts of negative refraction in metamaterials, while the second part of this project will concentrate on the differences of results between using different surface graphene conductivity models.