TY - JOUR AU - Feng, S. PY - 2014/02/15 Y2 - 2024/03/29 TI - Dual-Band Coherent Perfect Absorption/Thermal JF - Advanced Electromagnetics JA - AEM VL - 2 IS - 3 SE - Research Articles DO - 10.7716/aem.v2i3.230 UR - https://aemjournal.org/index.php/AEM/article/view/230 SP - 22-27 AB - <p>Dual-band perfect absorption/thermal emission is shown to be a general property of an ultrathin bilayer consisting of a dielectric and a totally reflective layer if the permittivity of the dielectric can be described by Drude-Lorentz (DL) model. &nbsp;The two bands coexist and reside on opposite sides of the Lorentzian resonant frequency where the material loss is small.&nbsp; However, the perfect absorption mechanism for the two bands is distinguishably different.&nbsp; One band is related to Fabry-Perot phenomenon and the surge of refractive index near the Lorentzian resonance.&nbsp; This band is polarization insensitive.&nbsp; The other band is associated with excitation of Brewster-type mode at the ϵ-near-zero (ENZ) wavelength and occurs only for p-polarized wave at oblique incidences.&nbsp; This mode has a fast-wave non-radiative character and propagates along the ultrathin ENZ layer superimposed on the highly reflective surface. &nbsp;Both bands exhibit wide-angle high emission with a small shift in their center frequencies which can be tuned by tuning the Lorentzian resonance.&nbsp; The resonance-enhanced dual band absorption occurs in the ultrathin DL layer at the weakly absorbing wavelengths as a consequence of an interaction between the total transmission and the total reflection.&nbsp; We demonstrate this phenomenon in a silicon carbide/copper bilayer.&nbsp; The suggested structure may have applications in biological and chemical sensors, IR sensors, thermal emission controls, thermophotovoltaics, and photodetectors.</p> ER -