Nonreciprocal wide-angle bidirectional absorber based on one-dimensional magnetized gyromagnetic photonic crystals

We propose magnetized gyromagnetic photonic crystals (MGPCs) composed of indium antimonide (InSb) and yttrium iron garnet ferrite (YIGF) layers, which possess the properties of nonreciprocal wide-angle bidirectional absorption. Periodical defects in the MGPCs work as filters. Absorption bands (ABs) for the positive and negative propagations arise from the optical Tamm state and resonance in cavities respectively, and they prove to share no overlaps in the studied frequency range. Given ω = 2.0138 THz, for the positive propagation, the ABs in the high-frequency range are localized in the interval between 0.66 ω and 0.88 ω. In the angular range, the ABs for the TE and TM waves reach 60° and 51°, separately. For the negative propagation, the ABs in the low-frequency range are localized in the interval between 0.13 ω and 0.3 ω. The ABs extend to 60° for the TE waves and 80.4° for the TM waves. There also exists a narrow frequency band in a lower frequency range. The relevant factors, which include the external temperature, the magnetic fields applied to the YIGF, the refractive index of the impedance matching layer, and the defect thickness, are adjusted to investigate the effects on the ABs. All the numerical simulations are based on the transfer matrix method. This work provides an approach to designs of isolators and so on.