A theoretical study based on coherent perfect absorption and polarization separation in one-dimensional magnetized plasma photonic crystals

Abstract

This article presents a study on tunable narrowband coherent perfect absorption (CPA), which can be altered by adjusting the initial phase to the ranges of 1.03α–1.13α (with α = 2πc/d) and 1.29α–1.43α. The relative bandwidths of these ranges are determined to be 8.5% and 7.4%, respectively. The study utilizes the transfer matrix method for calculations of the largest CPA amplitudes within one-dimensional (1D) magnetized plasma photonic crystals (MPPCs) across two absorption bands, achieving a maximum of 0.99 and 0.98, respectively. In addition, the phase modulation and amplitude modulation characteristics of the CPA are also discussed, and the results show that its absorption amplitude can be gradually modulated from 0.08 to 0.99 by the former and from 0.60 to 0.98 by the latter. The external magnetic fields have also been shown to limit the CPA amplitude between 0.41 and 0.99 within one band and between 0.52 and 0.99 within another band. The study further highlights the effect of plasma frequency and dielectric layer thickness on coherent band shifts towards high or low frequencies. Notably, the article presents the multiband polarization separation properties of 1D MPPCs, with calculated transmittance differences between the TM and TE waves of up to 0.70 and 0.74 at 1.13α and 1.37α, respectively.