Polarization Rotator between the Linear Polarization and the Circular Polarization Based on the Layered Photonic Structure

Abstract

AbstractA polarization rotator is investigated using a layered photonic structure composed of nonlinear media with the Kerr and single negative materials including epsilon‐negative media and mu‐negative media. Since the zero effective phase (expressed as zero‐φeff) bandgap formed by the alternating epsilon‐negative media and mu‐negative media has the characteristics of broadband phase retardation, as well as the nonlinear effect of the defect layer, the reflection phase difference and polarization form can be adjusted by the incident angle and light intensity. Studying the effect of those two parameters on reflectivity, reflection phase difference, and the polarization form under the forward and backward incidence, it is found that different incident directions can coherently tune the polarization form. By adjusting the incident angle and light intensity, the linear polarization can be converted to the left‐handed circular polarization in the forward incidence, and it can be converted to the right‐handed circular polarization in the backward incidence, thereby obtaining two different forms of circular polarization. Therefore, the different handed circularly polarized waves with relatively wide bandwidths can be obtained by changing the incident direction of electromagnetic waves, which provides the basis for tunable polarization selectors.