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Light Modulation with Vanadium Dioxide-Based Optical Devices


Kim, Yonghwi (2022) Light Modulation with Vanadium Dioxide-Based Optical Devices. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/pkxj-9584.


This thesis focuses on active material-based tunable optical devices. In particular, I have been working on tunable optical devices based on vanadium dioxide (VO2), which can produce tunable optical responses, such as amplitude, phase, thermal emission, and quantum emission. The modulations of light are achieved by coupling the phase-transition material with the precisely designed resonant structures or by placing it close to quantum emitters. This thesis presents three research streams, which aim at experimentally demonstrating the dynamically tunable optical responses using VO2. First, we propose and experimentally demonstrate an electrically tunable VO2-based reflectarray metasurface that exhibits largely tunable optical responses in the near-infrared region. We incorporate VO2 directly into the plasmonic resonator, which undergoes a phase transition triggered by Joule heating. The induced plasmonic resonance modulation is accompanied by a large and continuous modulation in optical responses, such as amplitude, resonance wavelength, and phase. Second, we propose and demonstrate an active tuning of thermal emission from VO2-based metasurfaces. We introduce a thin VO2 film as an absorbing layer on top of a metal reflector. This layer is coupled with a dielectric resonator, with a dielectric spacer placed between them. Upon undergoing a phase transition triggered by heating, the induced absorption tuning of the VO2 layer is accompanied by modulation in the absorption spectra of the coupled structure. We experimentally show narrowband absorption spectra, which can be tuned by controlling the VO2 temperature. Finally, we experimentally demonstrate the axial position of quantum emitters in a multilayered hexagonal boron nitride (hBN) flake with nanoscale accuracy, which is enabled through the modification of a photonic density of states by introducing VO2. Furthermore, we observe a sharp distance-dependent photoluminescence response by modulating the optical environment of an emitter placed close to the hBN/VO2 interface.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Vanadium Dioxide; Plasmonics; Nanophotonics; Active Metasurfaces; Thermal Emission; Quantum Emitters
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Atwater, Harry Albert
Group:Kavli Nanoscience Institute
Thesis Committee:
  • Faraon, Andrei (chair)
  • Atwater, Harry Albert
  • Scherer, Axel
  • Marandi, Alireza
Defense Date:18 June 2021
Non-Caltech Author Email:ykim.caltech (AT)
Record Number:CaltechTHESIS:06232021-050358035
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for Chapter 3. DocumentPatent adapted for Chapter 3. adapted for Chapter 5.
Kim, Yonghwi0000-0002-6652-7994
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14286
Deposited By: Yonghwi Kim
Deposited On:20 Jul 2021 17:43
Last Modified:08 Nov 2023 00:12

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