Energy deposition dynamics of femtosecond pulses in water

TL;DR

This study investigates how femtosecond laser pulses deposit energy in water, revealing a higher ionization energy than previously thought and introducing a new equation for Raman gain applicable to ultra-short pulses.

Contribution

The paper provides a quantitative analysis of energy loss and ionization in water using inverse Raman scattering and introduces a novel Raman gain equation for ultra-short pulses.

Findings

Ionization energy of water is 8 eV, higher than the commonly used 6.5 eV.

Validated the experimental approach with numerical simulations.

Introduced a new equation for Raman gain applicable to femtosecond pulses.

Abstract

We exploit inverse Raman scattering and solvated electron absorption to perform a quantitative characterization of the energy loss and ionization dynamics in water with tightly focused near-infrared femtosecond pulses. A comparison between experimental data and numerical simulations suggests that the ionization energy of water is 8 eV, rather than the commonly used value of 6.5 eV. We also introduce an equation for the Raman gain valid for ultra-short pulses that validates our experimental procedure.