Observation of ultrafast laser-plasma evolution by pump-probe reflectometry and Doppler spectrometry

TL;DR

This paper presents pump-probe techniques, Doppler spectrometry and reflectometry, to directly observe ultrafast laser-driven plasma dynamics at sub-100 femtoseconds, revealing shock and acoustic phenomena relevant to astrophysics and other fields.

Contribution

It introduces detailed pump-probe methods for capturing ultrafast plasma evolution, providing new insights into high-density plasma dynamics and transient phenomena.

Findings

Captured shock-like disturbances in dense plasma at >10^22/cc

Observed ultrafast acoustic phenomena during plasma expansion

Demonstrated sub-100 femtosecond temporal resolution

Abstract

We demonstrate pump-probe techniques, namely the Doppler spectrometry and the reflectometry in detail, which directly capture the time-resolved ultrafast evolution of high intensity femtosecond laser-driven hot, dense plasma. These techniques are capable of capturing ultrafast plasma dynamics on time scales of sub 100 femtosecond. We have shown the dynamics of high intensity femtosecond laser-driven shock like disturbance into the plasma at densities more than 10^22/cc. This can help understanding the physics related to shock ignition, supernova explosion and many other astrophysical scenarios and also can have implications in medicine and chemistry. Furthermore, we have investigated the ultrafast acoustic phenomena due to hydrodynamics inside an expanding hot, dense plasma in its transient phase by the correlated measurements of Doppler spectrometry and reflectometry.