Propagation of electromagnetic waves on quasiperiodic rare-earth multilayers

Abstract We analyze the reflection, transmission, and absorption spectra of electromagnetic waves in the visible frequency region, where a beam focuses perpendicularly and obliquely from a transparent medium (vacuum or air) on an aperiodic superlattice made up of rare-earth/SiO2 materials. The layers of the superlattice (or magnonic crystals) are organized following a growth rule that depends on the sequence studied. The types of binary sequences analyzed were Fibonacci, Thue-Morse, and double-period. The material that forms layer A is silicon dioxide (SiO2), and the material that forms layer B is a rare-earth (dysprosium or holmium). To find the reflectance, we used the transfer-matrix method in these superlattices by analyzing, through the normal and oblique incidences, the reflection spectrum, making a detailed comparison of the results obtained for both incidences. Our results show that Ho-comprised superlattices have a more transparent profile, and that the percentage of reflection depends strongly on polarization (s or p) for all considered sequences.