Open AccessMultiband coherent perfect absorption in a water-based metasurface
Author(s) -
Weiren Zhu,
Ivan D. Rukhlenko,
Fajun Xiao,
Chong He,
Junping Geng,
Xianling Liang,
Malin Premaratne,
Ronghong Jin
Publication year - 2017
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.25.015737
Subject(s) - optics , absorption (acoustics) , modulation (music) , molar absorptivity , phase (matter) , electromagnetic radiation , materials science , attenuation , phase modulation , physics , acoustics , phase noise , quantum mechanics
We design an ultrathin water-based metasurface capable of coherent perfect absorption (CPA) at radio frequencies. It is demonstrated that such a metasurface can almost completely absorb two symmetrically incident waves within four frequency bands, each having its own modulation depth of metasurface absorptivity. Specifically, the absorptivity at 557.2 MHz can be changed between 0.59% and 99.99% via the adjustment of the phase difference between the waves. The high angular tolerance of our metasurface is shown to enable strong CPA at oblique incidence, with the CPA frequency almost independent of the incident angle for TE waves and varying from 557.2 up to 584.2 MHz for TM waves. One can also reduce this frequency from 712.0 to 493.3 MHz while retaining strong coherent absorption by varying the water layer thickness. It is also show that the coherent absorption performance can be flexibly controlled by adjusting the temperature of water. The proposed metasurface is low-cost, biocompatible, and useful for electromagnetic modulation and switching.