Highly Confined Tunable Mid-Infrared Plasmonics in Graphene Nanoresonators
Abstract
Single-layer graphene has been shown to have intriguing prospects as a plasmonic material, as modes having plasmon wavelengths 20 times smaller than free space (λ_p ~ λ_0/20) have been observed in the 2–6 THz range, and active graphene plasmonic devices operating in that regime have been explored. However there is great interest in understanding the properties of graphene plasmons across the infrared spectrum, especially at energies exceeding the graphene optical phonon energy. We use infrared microscopy to observe the modes of tunable plasmonic graphene nanoresonator arrays as small as 15 nm. We map the wavevector-dependent dispersion relations for graphene plasmons at mid-infrared energies from measurements of resonant frequency changes with nanoresonator width. By tuning resonator width and charge density, we probe graphene plasmons with λ_p ≤ λ_0/100 and plasmon resonances as high as 310 meV (2500 cm^–1) for 15 nm nanoresonators. Electromagnetic calculations suggest that the confined plasmonic modes have a local density of optical states more than 10^6 larger than free space and thus could strongly increase light–matter interactions at infrared energies.
Additional Information
© 2013 American Chemical Society. Received: February 15, 2013; Revised: April 11, 2013; Published: April 26, 2013. While preparing this manuscript, we became aware of two recent works studying mid-infrared plasmon resonances on graphene. The authors gratefully acknowledge support from the Air Force Office of Scientific Research Quantum Metaphotonic MURI program under grant FA9550-12-1-0488 and use of facilities of the DOE "Light-Material Interactions in Energy Conversion" Energy Frontier Research Center (DESC0001293). V.W.B. gratefully acknowledges a postdoctoral fellowship from the Kavli Nanoscience Institute. The authors are thankful for helpful discussions with J. Fakonas, S. Burgos, S. Kim, L. Ju, R. Weitekamp, E. Kosten, M. Sheldon, and D. Callahan.Attached Files
Supplemental Material - nl400601c_si_001.pdf
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Additional details
- Eprint ID
- 39918
- Resolver ID
- CaltechAUTHORS:20130814-142610055
- Air Force Office of Scientific Research (AFOSR)
- FA9550-12-1-0488
- Department of Energy (DOE)
- DE-SC0001293
- Kavli Nanoscience Institute
- Created
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2013-08-14Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute