Hybrid optical antennas with photonic resistors

TitleHybrid optical antennas with photonic resistors
Publication TypeJournal Article
Year of Publication2015
AuthorsButakov NA, Schuller JA
JournalOptics Express
Date Publishednov
Keywords21975, AFOSR, CNSI/MRL, CSC, DOD-Grad, FBNS02, Infrared, Metamaterials, Modulation techniques, MRL, Nanophotonics and photonic crystals, Optical switching devices, Resonators, Schuller, Subwavelength structures

Hybrid optical antennas, comprising active materials placed in the gaps of plasmonic split-ring-resonators and nano-dimers, have been the subject of numerous recent investigations. Engineered coupling between the two plasmonic resonators is achieved by modulating the active material, enabling control over the near- and far-field electromagnetic properties. Here, using electromagnetics calculations, we study the evolving optical response of a hybrid metal-semiconductor-metal nanorod antenna as the semiconductor free charge carrier density is continuously varied. In particular, we demonstrate qualitatively new behavior arising from epsilon-near-zero properties in intermediately doped semiconductors. In agreement with optical nano-circuit theory, we show that in the epsilon-near-zero regime such a load acts as an ideal optical resistor with an optimized damping response and strongly suppressed electromagnetic scattering. In periodic arrays, or metasurfaces, we then show how to use these effects to construct high-efficiency nanophotonic intensity modulators for dynamically shaping light.

MRI R2 (CNS-0960316), CSC, MRL (DMR-1121053)