Measurement of amplification and absorption of a THz quantum-cascade metasurface free-space amplifier
Abstract
An active amplifying metasurface based on a quantum-cascade gain material at 2.7 THz is studied. The metasurface is first evaluated as the active component of an external cavity laser with excellent beam quality and frequency tunability from 2.55–2.8 THz. Amplification and absorption of the metasurface alone are then separately measured at a single frequency using a probe signal from a CO2-pumped gas laser operating at 2.743 THz. The metasurface reflectance vs bias is measured and compared with expectations from non-equilibrium Green’s function simulations of the quantum-cascade gain material and FEM simulations of the metasurface reflectance. A peak amplification on the order of 0.3 dB is measured. Design strategies are discussed for increasing single-reflection amplification (upward of 10 dB) and reducing power dissipation. Further increased amplification could be achieved by cascading multiple metasurfaces.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 01, 2022
- Source ID
- 10.1063/5.0122154
Entities
People
- Benjamin S. Williams
- Boris S. Karasik
- Christopher A. Curwen
- John L. Reno
- Jonathan H. Kawamura
- Mohammad Shahili
- Sadhvikas Addamane
Organizations
- California Institute of Technology
- Jet Propulsion Laboratory
- National Aeronautics and Space Administration
- National Nuclear Security Administration
- Sandia National Laboratories
- University of California