On the Optical Properties of Thin‐Film Vanadium Dioxide from the Visible to the Far Infrared
Abstract
The insulator‐to‐metal transition (IMT) in vanadium dioxide (VO2) can enable a variety of optics applications, including switching and modulation, optical limiting, and tuning of optical resonators. Despite the widespread interest in VO2 for optics, the wavelength‐dependent optical properties across its IMT are scattered throughout the literature, are sometimes contradictory, and are not available at all in some wavelength regions. Here, the complex refractive index of VO2 thin films across the IMT is characterized for free‐space wavelengths from 300 nm to 30 µm, using broadband spectroscopic ellipsometry, reflection spectroscopy, and the application of effective‐medium theory. VO2 films of different thicknesses are studied, on two different substrates (silicon and sapphire), and grown using different synthesis methods (sputtering and sol–gel). While there are differences in the optical properties of VO2 synthesized under different conditions, these differences are surprisingly small in the ≈2–11 µm range where the insulating phase of VO2 also has relatively low optical loss. It is anticipated that the refractive‐index datasets from this article will be broadly useful for modeling and design of VO2‐based optical and optoelectronic components, especially in the mid‐wave and long‐wave infrared.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 20, 2019
- Source ID
- 10.1002/andp.201900188
Entities
People
- Alireza Shahsafi
- Carsten Ronning
- Chenghao Wan
- Colin M. Hessel
- David Woolf
- Jad Salman
- Joel M. Hensley
- Jura Rensberg
- M. M. Qazilbash
- Mikhail A Kats
- Rüdiger Schmidt‐grund
- Shriram Ramanathan
- Steffen Richter
- Yifei Sun
- Yuzhe Xiao
- Zhen Zhang
Organizations
- College of William & Mary
- Friedrich Schiller University Jena
- German Research Foundation
- Leipzig University
- National Science Foundation
- Office of Naval Research
- Purdue University
- Technische Universität Ilmenau
- United States Naval Research Laboratory
- University of Wisconsin–Madison