Faster than light in a birefringent crystal

TL;DR

This paper investigates superluminal signal propagation in birefringent crystals, analyzing the phenomenon through stationary phase and gaussian wave transit, and establishing bounds for the effect's validity.

Contribution

It provides a detailed analysis of superluminal effects in birefringent crystals using both stationary phase and gaussian wave approaches, clarifying the conditions for such phenomena.

Findings

Superluminal propagation observed without absorption or reflection

Stationary phase analysis aligns with previous results

Bounds established for gaussian wave transit validity

Abstract

We examine the effect of superluminal signal propagation through a birefringent crystal, where the effect is not due to absorption or reflection, but to the filtration of a special polarization component. We first examine the effect by a stationary phase analysis, with results consistent with those of an earlier analysis of the system. We supplement this analysis by considering the transit of a gaussian wave and find bounds for the validity of the stationary phase result. The propagation of the gaussian wave is illustrated by figures.