Negative refraction and left-handed behavior in two-dimensional photonic crystals

TL;DR

This paper investigates the conditions under which two-dimensional photonic crystals exhibit negative refraction and left-handed behavior, emphasizing the distinction between negative refraction and true negative index of refraction through detailed velocity and index analysis.

Contribution

It provides a systematic analysis of the criteria for LH behavior in photonic crystals and proposes an experimental method to distinguish negative refraction with and without LH behavior.

Findings

Negative refraction does not necessarily imply LH behavior.

Phase and group velocity analyses are crucial for identifying LH behavior.

A wedge experiment can unambiguously differentiate cases of negative refraction with LH behavior.

Abstract

We systematically examine the conditions of obtaining left-handed (LH) behavior in photonic crystals. Detailed studies of the phase and group velocities as well as the phase np and group ng refractive index are given. The existence of negative refraction does not guarantee the existence of negative index of refraction and so LH behavior. A wedge type of experiment is suggested that can unambiguously distiguinsh between cases of negative refraction that occur when left-handed behavior is present, from cases that show negative refraction without LH behavior.