Open AccessTransforming zero-index media into geometry-invariant coherent perfect absorbers via embedded conductive films
Author(s) -
Dunjian Wang,
Jie Luo,
Sun Zhen,
Yun Lai
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.416632
Subject(s) - optics , electrical conductor , photonics , physics , photonic crystal , refractive index , materials science , embedding , zero (linguistics) , perfect conductor , absorption (acoustics) , dielectric , optoelectronics , quantum mechanics , scattering , computer science , linguistics , philosophy , artificial intelligence
In this work, we demonstrate an approach to realize geometry-invariant multi-channel coherent perfect absorbers by embedding ultrathin conductive films in zero-index media. Coherent perfect absorption can be achieved for waves incidents from an arbitrary number of input channels as long as the total width of the channels equals to a critical value that is only determined by the length and material parameters of the conductive films instead of their shapes and positions. The absorption attributes to induced currents in the conductive films by the electric fields of incidence, and the shape- and position-independent characteristics originate from the uniformly distributed electric fields inside the zero-index media. By using dielectric photonic crystals and photonic-doped zero-index media, we numerically demonstrate such an interesting transformation from zero-index media to coherent perfect absorbers. Furthermore, ultrathin coherent perfect absorbers based on zero-index media are also demonstrated in waveguides. Our work reveals a unique mechanism to change the material responses between zero-index media and coherent perfect absorbers.