Extreme energy density confined inside a transparent crystal: Solid - plasma - solid transformations, status and perspectives

TL;DR

This paper reviews the use of ultrashort laser pulses, especially Bessel beams, to achieve extreme energy densities inside transparent crystals, enabling novel solid-plasma-solid transformations and high-pressure phase formations.

Contribution

It discusses the potential of Bessel-shaped laser pulses to surpass Gaussian pulses in energy density and material transformation capabilities.

Findings

Bessel beams can transform larger material volumes.

Higher energy densities are achievable with Bessel pulses.

Potential for creating new high-pressure material phases.

Abstract

It was demonstrated during the past decade that ultrashort intense laser pulse tightly focused deep inside a transparent dielectric generates the energy density in excess of several MJ/cm3. Such energy concentration with extremely high heating and quenching rates leads to unusual solid-plasma-solid transformation paths overcoming kinetic barriers to formation of previously unknown high-pressure material phases, which are preserved in the surrounding pristine crystal. These results were obtained with the pulse of Gaussian shape in space and in time. Recently it was shown that the Bessel-shaped pulse could transform much larger amount of a material and allegedly create even higher energy density than that was achieved with the Gaussian (GB) pulses. Here we present a succinct review of previous results and discuss the possible routes for achieving higher energy density employing the Bessel beams (BB) and take advantage of its unique properties.