Harmonic-seeded remote laser emissions in N2-Ar, N2-Xe and N2-Ne mixtures: a comparative study

TL;DR

This study compares harmonic-seeded remote laser emissions at 391 nm in N2-Ar, N2-Xe, and N2-Ne mixtures, revealing how different gases affect laser intensity and amplification due to filament dynamics and seed strength.

Contribution

It provides a comparative analysis of how various gas mixtures influence remote laser emissions seeded by harmonics, highlighting the roles of filament properties and seed strength.

Findings

N2-Xe mixture shows decreased laser intensity due to lower clamped intensity.

N2-Ne mixture exhibits slight increase in laser intensity with higher clamped intensity.

N2-Ar mixture achieves significant enhancement owing to stronger third harmonic seed and longer filament.

Abstract

We report on the investigation on harmonic-seeded remote laser emissions at 391 nm wavelength from strong-field ionized nitrogen molecules in three different gas mixtures, i.e., N2-Ar, N2-Xe and N2-Ne. We observed a decrease in the remote laser intensity in the N2-Xe mixture because of the decreased clamped intensity in the filament; whereas in the N2-Ne mixture, the remote laser intensity slightly increases because of the increased clamped intensity within the filament. Remarkably, although the clamped intensity in the filament remains nearly unchanged in the N2-Ar mixture because of the similar ionization potentials of N2 and Ar, a significant enhancement of the lasing emission is realized in the N2-Ar mixture. The enhancement is attributed to the stronger third harmonic seed, and longer gain medium due to the extended filament.