# Leaky modes of a left-handed slab

## TL;DR

This paper analyzes the leaky modes in left-handed slabs, revealing their backward nature, connection to right-handed slabs, and explaining negative lateral shifts through mode excitation.

## Contribution

It introduces a complex plane analysis to characterize leaky modes in left-handed slabs and their relation to right-handed counterparts, providing new insights into wave behavior.

## Key findings

- Left-handed slabs support backward leaky slab and surface waves.
- Leaky modes are excited at the same incidence angles as in right-handed slabs.
- Negative giant lateral shifts are explained by leaky mode excitation.

## Abstract

Using complex plane analysis we show that left-handed slab may support either leaky slab waves, which are backward because of negative refraction, or leaky surface waves, which are backward or forward depending on the propagation direction of the surface wave itself. Moreover, there is a general connection between the reflection coefficient of the left-handed slab and the one of the corresponding right-handed slab (with opposite permittivity and permeability) so that leaky slab modes are excited for the same angle of incidence of the impinging beam for both structures. Many negative giant lateral shifts can be explained by the excitation of these leaky modes.