Transient gain from $N_2^+$ in light filaments

TL;DR

This paper investigates the transient optical gain in nitrogen molecular ions within light filaments, revealing that resonant stimulated Raman scattering is responsible for the observed gain through high-resolution spectroscopy.

Contribution

It demonstrates that transient gain in $N_2^+$ is caused by resonant stimulated Raman scattering, providing new insights into light filament interactions with molecular ions.

Findings

Transient gain is achieved by resonant stimulated Raman scattering.

High-resolution spectroscopy confirms the gain mechanism.

The study advances understanding of light filament ion interactions.

Abstract

We perform high resolution spectroscopy of $N_2^+$ emission in light filaments using a controlled pump at 795 followed by a second harmonic weak probe. Our result suggests that transient gain is achieved by resonant stimulated Raman scattering.