Frequency spectra in the ATR mode of ellipsometric parameters of a periodic medium with a resonant defect in which polaritons are excited

Volgograd State University, 100, Universitetskiy pr., Volgograd, 400062, Russia

^* Corresponding author: valeryyat@gmail.com

Published online: 17 February 2025

Abstract

The work is devoted to the study of ellipsometry parameters of elliptically polarized light reflected from a layered system in the ATR mode. Two cases were considered. In the first case, reflection occurs from an ideal periodic layered system of 10 pairs of layers. In the second case, the 10th layer is replaced with a resonant semiconductor InSb, which acts as a defect in the periodic structure. The dielectric constant of this layer exhibits a strong resonant frequency dependence, resulting in the excitation of polaritons with a mixed electromagnetic and mechanical nature. The study demonstrates that the presence of a resonant defect significantly affects the ellipsometric parameters of light reflected from the layered system. This phenomenon can be utilized to investigate the optical properties of resonant semiconductors in which polaritons are excited. Furthermore, in this layered system with an embedded foreign object, a change in the nature of polarization occurs when circularly polarized light is reflected from it. Under certain conditions, it is shown that left-handed circularly polarized light initially incident on the layered system transforms upon reflection into elliptically polarized light with right-handed polarization. This effect has potential applications in devices designed for light polarization conversion.