(IEEE, 2024-10-08) Lezaun Capdevila, Carlos; Navajas Hernández, David; Liberal Olleta, Íñigo; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Light absorption is a key phenomenon for a variety of technologies [1]: radiative cooling, photovoltaics, sensing, communication and camouflaging are just a few examples. These applications demand scalable and compact devices that modulate their absorption spectra, usually engineered using cavities and/or periodic structures acting as resonators. Weak light matter interaction limits the absorption within ultra-compact devices, although epsilon-near-zero (ENZ) materials allows to greatly increase such interaction [2]. The lack of design standardization presents a big gap for designing absorbers. We present a thorough analysis of an arbitrary material on top of a PEC (perfect electric reflector) and a material separated by a spacer from the PEC. We overview the absorption phenomena for different permittivity regions, thicknesses, angles of incidence and polarization. This work helps standardize the design of these absorber configuration.
(IEEE, 2024-10-08) Lezaun Capdevila, Carlos; Navajas Hernández, David; Liberal Olleta, Íñigo; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Light absorbers are key components for multiple applications ranging from heat and energy management to communications and sensing. This work explores different complex permittivity combinations for material-reflector and material-spacer-reflector configurations, achieving perfect absorption under different permittivity regimes and thicknesses. Using silicon carbide, we discuss polarization and angle dependencies, and the potential of exploiting different permittivity regimes within a device for multi-band absorption. This work helps standardize absorber design and offer insights to engineer perfect absorbers for applications such as thermal emission, absorption, communication and sensing.
