Resonant absorption in semiconductor nanowires and nanowire arrays: Relating leaky waveguide modes to Bloch photonic crystal modes
Abstract
We present a unified framework for resonant absorption in periodic arrays of high index semiconductor nanowires that combines a leaky waveguide theory perspective and that of photonic crystals supporting Bloch modes, as array density transitions from sparse to dense. Full dispersion relations are calculated for each mode at varying illumination angles using the eigenvalue equation for leaky waveguide modes of an infinite dielectric cylinder. The dispersion relations along with symmetry arguments explain the selectivity of mode excitation and spectral red-shifting of absorption for illumination parallel to the nanowire axis in comparison to perpendicular illumination. Analysis of photonic crystal band dispersion for varying array density illustrates that the modes responsible for resonant nanowire absorption emerge from the leaky waveguide modes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 21, 2014
- Source ID
- 10.1063/1.4898758
Entities
People
- Harry Atwater
- Katherine T. Fountaine
- William S. Whitney
Organizations
- California Institute of Technology
- National Science Foundation
- United States Department of Defense
- United States Department of Energy