Ultra-wide unidirectional infrared absorber based on 1D gyromagnetic photonic crystals concatenated with general Fibonacci quasi-periodic structure in transverse magnetization

In this paper, an ultra-wide multiband unidirectional absorber based on 1D gyromagnetic magnetized photonic crystals (GMPCs) comprising ferrite material and isotropic dielectrics is investigated under transverse magnetization for transverse electric mode within the infrared regime by the transfer matrix method. Due to the Voigt magneto-optical effect, the magnetically modulated absorber possesses multiple preeminent one-way absorption bands, which run at 12.24–18.80, 25.25–50.05, 51.13–74.90 and 76.67–93.88 THz and in the reverse propagating direction. The absorber displays a splendid reflection phenomenon. These perfect nonreciprocal results can be ascribed to the destruction of the space-time reversal symmetry on account of the anisotropic gyromagnetic ferrite material and quasi-periodic arrangement of the proposed GMPCs. The comparisons of the absorption capacity among the general Fibonacci sequence, the periodic sequence and Thue–Morse sequence are discussed, and the general Fibonacci sequence has its superiority in the expansion of the one-way absorption bandwidth due to its better self-similarity. Besides, the regulative effects of the magnetic field intensity, damping factor and thicknesses of materials on the one-way absorption features are analyzed specifically. This research provides a promising design approach to the tunable infrared optical isolator, waveguide and circulator through the magnetized materials.