Broadband, High‐Speed, and Large‐Amplitude Dynamic Optical Switching with Yttrium‐Doped Cadmium Oxide
Abstract
Transparent conducting oxides, such as doped indium oxide, zinc oxide, and cadmium oxide (CdO), have recently attracted attention as tailorable materials for applications in nanophotonic and plasmonic devices such as low‐loss modulators and all‐optical switches due to their tunable optical properties, fast optical response, and low losses. In this work, optically induced extraordinarily large reflection changes (up to 135%) are demonstrated in bulk CdO films in the mid‐infrared wavelength range close to the epsilon near zero (ENZ) point. To develop a better understanding of how doping level affects the static and dynamic optical properties of CdO, the evolution of the optical properties with yttrium (Y) doping is investigated. An increase in the metallicity and a blueshift of the ENZ point with increasing Y‐concentrations is observed. Broadband all‐optical switching from near‐infrared to mid‐infrared wavelengths is demonstrated. The major photoexcited carrier relaxation mechanisms in CdO are identified and it is shown that the relaxation times can be significantly reduced by increasing the dopant concentration in the film. This work could pave the way to practical dynamic and passive optical and plasmonic devices with doped CdO spanning wavelengths from the ultraviolet to the mid‐infrared region.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 13, 2019
- Source ID
- 10.1002/adfm.201908377
Entities
People
- Alexandra Boltasseva
- Aveek Dutta
- Benjamin T Diroll
- Joshua Shank
- Michael G Wood
- Richard D. Schaller
- Salvatore Campione
- Sarah N. Chowdhury
- Soham Saha
- Ting Shan Luk
- Vladimir Shalaev
- Zhaxylyk Kudyshev
Organizations
- Air Force Office of Scientific Research
- Argonne National Laboratory
- Birck Nanotechnology Center, Purdue University
- National Nuclear Security Administration
- Northwestern University
- Office of Basic Energy Sciences
- Office of Science
- Purdue University
- Sandia National Laboratories
- United States Department of Energy