Widely Tunable Infrared Antennas Using Free Carrier Refraction

Tomer Lewi, Prasad P. Iyer, Nikita A. Butakov, Alexander A. Mikhailovsky, Jon A. Schuller

Research output: Contribution to journalArticlepeer-review

80 Scopus citations


We demonstrate tuning of infrared Mie resonances by varying the carrier concentration in doped semiconductor antennas. We fabricate spherical silicon and germanium particles of varying sizes and doping concentrations. Single-particle infrared spectra reveal electric and magnetic dipole, quadrupole, and hexapole resonances. We subsequently demonstrate doping-dependent frequency shifts that follow simple Drude models, culminating in the emergence of plasmonic resonances at high doping levels and long wavelengths. These findings demonstrate the potential for actively tuning infrared Mie resonances by optically or electrically modulating charge carrier densities, thus providing an excellent platform for tunable metamaterials.

Original languageEnglish
Pages (from-to)8188-8193
Number of pages6
JournalNano Letters
Issue number12
StatePublished - 9 Dec 2015
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2015 American Chemical Society.


  • Mie resonators
  • Optical antennas
  • free carrier refraction
  • semiconductor nanoparticles
  • silicon photonics
  • tunable metamaterials


Dive into the research topics of 'Widely Tunable Infrared Antennas Using Free Carrier Refraction'. Together they form a unique fingerprint.

Cite this