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Updated: Aug 19, 2025
08:01
Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
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Substrate-mediated hyperbolic phonon polaritons in MoO3.
Jeffrey J Schwartz1,2, Son T Le1,3, Sergiy Krylyuk4
1Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Nanophotonics (Berlin, Germany)
|December 1, 2022
Summary
Hyperbolic phonon polaritons (HPhPs) in alpha-molybdenum trioxide (α-MoO3) exhibit long lifetimes and propagation distances. Substrate engineering can enhance these properties for advanced nanophotonic applications.
Area of Science:
- Nanophotonics
- Condensed Matter Physics
- Materials Science
Background:
- Hyperbolic phonon polaritons (HPhPs) are light-matter hybrid excitations in anisotropic materials.
- Two-dimensional materials like MoO3 offer potential for mid-infrared nanophotonics due to HPhPs.
- HPhPs enable light confinement to sub-diffractional dimensions.
Purpose of the Study:
- To determine the dispersion relations and lifetimes of HPhPs in single-crystalline α-MoO3.
- To investigate the impact of substrate interactions and defects on HPhP propagation.
- To explore substrate-defined nanophotonic structures using layered anisotropic materials.
Main Methods:
- Photothermal induced resonance (PTIR) technique for nanoscale imaging.
- Fourier analysis of real-space polariton images.
- Characterization of MoO3 crystals on periodic gratings.
Main Results:
- HPhP lifetimes up to ≈12 ps were measured in α-MoO3.
- Suspended MoO3 regions showed ≈2× longer HPhP propagation lengths and lifetimes compared to substrate-contacted regions.
- Subsurface defects and polymeric contaminants had negligible effects on HPhP propagation.
Conclusions:
- Substrate engineering significantly influences HPhP propagation in α-MoO3.
- Suspended structures enhance HPhP performance for nanophotonic applications.
- PTIR is effective for characterizing HPhPs and material properties, including defects and contaminants.
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