Exploiting the metal-insulator transition of VO2 thin films for terahertz wave modulation and switching

Md Nadim Ferdous Hoque, Gulten Karaoglan-Bebek, Mark Holtz, Ayrton A. Bemussi, Zhaoyang Fan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

VO2 is one of the very few natural materials that can be used to modulate terahertz (THz) radiations. A 100-nm thick VO2, when in its metallic phase, has a charge density of more than ∼ 1015 cm-2 which will strongly reflect and absorb the THz radiation; while in its insulator state, the charge density is lowered by several orders of magnitude to be THz transparent. Therefore, exploiting the metal-insulator transition of VO2 is a potential approach to modulate or even switch THz radiation for THz optics. Here we report that VO2 epitaxial thin films on sapphire substrate exhibits 85% amplitude modulation depth in a broad bandwidth, while this value can be improved to 95% when VO2 film is coated on both sides of a substrate. We further demonstrate that with wafer bonding, 4-layered VO2 thin films exhibit a transmittance as low as -20 dB to -30 dB at their metallic state, enough for switching applications. We also report our proof-of-concept demonstration of THz spatial light modulator that exhibits amplitude modulation as large as 96%, -30 dB pixel-to-pixel crosstalk, and a broad THz bandwidth.

Original languageEnglish (US)
Title of host publication2015 Materials Research Society Symposium Proceedings
Subtitle of host publicationFabrication and Properties of Oxide Thin Films, Nanostructures and Interfaces for Advanced Applications
EditorsJ. Augustynski, F. Grosse, D. Kumar, F. Sanchez, C. Santato, X.W. Sun, A. Vomiero, T. Yamamoto
PublisherMaterials Research Society
Pages55-60
Number of pages6
Volume1805
ISBN (Electronic)9781510872325
DOIs
StatePublished - 2015
Externally publishedYes
Event2015 MRS Spring Meeting on Fabrication and Properties of Oxide Thin Films, Nanostructures and Interfaces for Advanced Applications - San Francisco, United States
Duration: Apr 6 2015Apr 10 2015

Conference

Conference2015 MRS Spring Meeting on Fabrication and Properties of Oxide Thin Films, Nanostructures and Interfaces for Advanced Applications
Country/TerritoryUnited States
CitySan Francisco
Period4/6/154/10/15

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Science(all)
  • Condensed Matter Physics

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