Development of a two-color interferometer for observing wide range electron density profiles with a femtosecond time resolution

Abstract

A two-color interferometer for preformed plasma characterization is developed. We observe the electron density distribution of preformed plasmas on a 5 mu m-thick copper target irradiated with a high-intensity Ti:sapphire laser. The two-color interferometer extended the observable electron density region using a fundamental (800 nm) probe beam to cover the lower density region and a second harmonic (400 nm) probe beam to cover the higher density region, simultaneously. This characterization of the electron density distribution of preformed plasmas with femtosecond time resolution significantly contributes to the understanding of high-intensity laser-thin-foil interactions during high-energy electron, ion, and X-ray generation.