Effects of normal and oblique incidence on zero-n gap in periodic lossy multilayer containing double-negative materials

TL;DR

This study investigates how the zero-n gap in a lossy photonic crystal with negative and positive index layers varies with incidence angle, polarization, and layer ratios, informing optical device design.

Contribution

It provides new insights into the sensitivity of the zero-n gap to incidence angle, polarization, and layer ratios in lossy multilayer structures containing double-negative materials.

Findings

Zero-n gap is highly sensitive to incidence angle and polarization.

The gap is nearly insensitive to small loss factors.

Layer thickness ratios significantly affect the zero-n gap properties.

Abstract

In this paper the transmission of electromagnetic waves through a one-dimensional lossy photonic crystal consisting of layers with negative and positive refractive indices is investigated. The behavior and characteristics of the bandwidth, the depth and the central frequency of the zero-n gap for different incidence angles, polarization, loss factor and ratios of thickness of the layers are studied. The results show that the gap is very sensitive to the incidence angle, polarization and the thickness ratio, but it is nearly insensitive to small loss factor. Such properties are quite useful in designing new types of edge filters and other optical devices in microwave engineering.