Review Article
Arissian L and Diels JC
Abstract
In the case of gases weakly ionized with ultra-short pulses, the electrons that follow the laser field are neither bound nor free. This review paper presents a simple approach to calculate the electron index based on a known electron motion in a non-relativistic regime. This basic approach does not neglect the time varying index. This review is an effort to capture concepts of the transient electron index, like the electron index created in the laser filamentation.