Truncated spherical voids for nearly omnidirectional optical absorption

Opt Express. 2011 Oct 10;19(21):20642-9. doi: 10.1364/OE.19.020642.

Abstract

Truncated spherical voids nanostructured tungsten films are shown to have nearly perfect absorption with characteristics of broad-band, polarization-independent and wide-incidence angle in near infrared and visible regime. Through optimizing material and structural parameters, we can achieve the absorbance above 90% from 420THz to 600THz within incidence angle from 0° to 60° for TE polarization and from 450THz to 800THz within incidence angle from 0° to 75° for TM polarization. In particular, absorbance can achieve 99.9% at 550.5THz for both polarizations under normal incidence. Such strong absorption is explained using multilayer effective media theory and cavity resonance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Computer Simulation
  • Equipment Design
  • Materials Testing
  • Models, Statistical
  • Nanostructures / chemistry
  • Nanotechnology / methods
  • Optics and Photonics*
  • Spectrophotometry / methods*
  • Spectrophotometry, Infrared / methods