Stable intense 1 kHz supercontinuum light generation in air

TL;DR

This paper demonstrates stable, high-energy supercontinuum light generation in air at 1 kHz by applying an external electric field, significantly reducing jitters and enabling new applications in laser filamentation.

Contribution

It introduces a novel method of applying an external electric field to air plasma filaments to achieve stable supercontinuum generation at kHz repetition rates.

Findings

Jitter reduction by more than 2 times in pointing and intensity.

Successful generation of multi-mJ level supercontinuum in air.

Enhanced stability of supercontinuum light suitable for practical applications.

Abstract

Supercontinuum (SC) light source has advanced ultrafast laser spectroscopy in condensed matter science, biology, physics, and chemistry. Compared to the frequently used photonic crystal fibers and bulk materials, femtosecond laser filamentation in gases is damage-immune for supercontinuum generation. A bottleneck problem is the strong jitters from filament induced self-heating at kHz repetition rate level. We demonstrate stable kHz supercontinuum generation directly in air with multiple mJ level pulse energy. This is achieved by applying an external DC electric field to the air plasma filament through the effects of plasma wave guiding and Coulomb interaction. Both pointing and intensity jitters of 1 kHz air filament induced SC light are reduced by more than 2 fold. This offers the opportunities for stable intense SC generation and other laser filament based applications in air.