Control of directionality of light with active and passive silicon nanostructures

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Abstract/Contents

Abstract
Semiconductor nanoantennas have recently emerged as very promising platforms for light manipulation at the nanoscale. More specifically, Silicon has become very popular among researchers thanks to its strong light-matter interaction features, mature fabrication technology availabilities, potential for serving simultaneous optical and electronic purposes, and significantly lower losses compared to its metallic competitors. In this thesis, we employed two main architectures that help us achieve our ultimate goal of controlling the light emission and scattering properties in the nanoscale. In the first architecture, we utilize Si nanowires as our nanoantennas to control the emission directionality of 2D monolayer MoS2 emitters, where our choice of emitter material was based on the attractive properties and recent popularity of 2D materials emitting in the visible range of the spectrum. In this Si- MoS2 configuration, we demonstrate more than 25 top-to-bottom emission ratio enhancement with Si NWs compared to bare MoS2 emission. By using NWs of different radii, we demonstrated such directionality by two different mechanisms which were fundamentally different in terms of the excited resonances in the NW. While targeting directionality, we also observed strong polarization selectivity and spectral modification of the operation principles which gave us the power to tune the spectral and polarization properties of the dominant top emission of this system. As the next step, we aimed to demonstrate an active and on-demand control of directionality of scattering of plane-waves. To achieve this, we designed, fabricated and characterized a Si MEMS architecture that enabled us to observe more than 30° active control of angular emission with the application of 5 V potential.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2018; ©2018
Publication date 2018; 2018
Issuance monographic
Language English

Creators/Contributors

Author Cihan, Ahmet Fatih
Degree supervisor Brongersma, Mark L
Thesis advisor Brongersma, Mark L
Thesis advisor Fan, Shanhui, 1972-
Thesis advisor Vuckovic, Jelena
Degree committee member Fan, Shanhui, 1972-
Degree committee member Vuckovic, Jelena
Associated with Stanford University, Department of Electrical Engineering.

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Ahmet Fatih Cihan.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis Ph.D. Stanford University 2018.
Location electronic resource

Access conditions

Copyright
© 2018 by Ahmet Fatih Cihan
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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