Wide-Angle and Ultra-Wideband Absorption in One-Dimensional Superconductor Photonic Crystals With Quasi-Periodic Sequences

In this paper, the properties of wide-angle and ultra-wideband (UWB) absorption of one-dimensional (1-D) superconductor photonic crystals (SPCs) in the terahertz (THz) region are theoretically analyzed by transfer matrix method (TMM). We principally study the absorption features in SPCs with different arrangements by contrast where their external factors and dielectric types are consistent. The arrangements of SPCs adopt two construction rules of generous Fibonacci sequence (GFS) and Cantor-like sequence (CLS). In addition, the influences of the recursive numbers, external factors and polarization-depend properties on the proposed structures are also considered. We introduce multifractal theory to describe the absorption trends and self-similarity of quasi-periodic structural system subtly specific to the variation of recursive numbers. Moreover, the reason for angle-insensitive absorption is also investigated via the interference field theory. The calculated results demonstrate that the UWB absorption can sustain over 80 degrees within THz region for transverse magnetic (TM) wave at high temperature in the proposed SPCs, which provides theoretical guidance for the design of the high-performance THz absorber.