Thermally tunable terahertz metasurface absorber based on all dielectric indium antimonide resonator structure

Abstract

In this paper, we present a novel design of temperature tunable metasurface absorber (MSA) based on all dielectric indium antimonide (InSb) resonator structure in terahertz (THz) region. The permittivity of the InSb dielectric is dependent on the variation of temperature. Based on the perfect impedance-match (Re(z)≈1) to the free space, the absorbance of the proposed MSA is up to 99.9% at 1.43 THz and the Q-factor is about 26.9 when temperature is 285 K. The perfect absorption of the MSA is mainly from excitation of fundamental dipolar mode. In addition, the MSA is polarization-insensitive for both transverse electric (TE) and transverse magnetic (TM) waves. Furthermore, the absorption properties of the MSA can be adjusted by changing the geometric parameters of the unit-cell structure and temperature. The design offers a new route for control of THz absorption with potential applications in imaging, energy harvesting, sensing, and detecting.