Open AccessTruncated spherical voids for nearly omnidirectional optical absorption
Author(s) -
Min Wang,
Chenggang Hu,
Mingbo Pu,
Cheng Huang,
Zeyu Zhao,
Feng Qin,
Xiangang Luo
Publication year - 2011
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.020642
Subject(s) - optics , absorbance , materials science , polarization (electrochemistry) , brewster's angle , absorption (acoustics) , refractive index , transmittance , angle of incidence (optics) , absorption band , optoelectronics , physics , chemistry , brewster
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.