Ultra-broadband UV/VIS spectroscopy enabled by resonant dispersive wave emission of a frequency comb

TL;DR

This paper presents a new ultra-broadband UV/VIS light source based on resonant dispersive wave emission in a gas-filled fiber, enabling advanced spectroscopy with high coherence and tunability across a wide spectral range.

Contribution

The authors demonstrate a novel ultra-broadband UV/VIS frequency comb source with over 240 THz coverage, high conversion efficiency, and preserved coherence, advancing spectroscopy capabilities.

Findings

Achieved tunable UV/VIS coverage from 340 nm to 465 nm.

Demonstrated absorption spectroscopy of nitrogen dioxide.

Maintained coherence of the frequency comb during up-conversion.

Abstract

We introduce a novel ultra-broadband ultraviolet and visible frequency comb light source covering more than 240 THz by resonant dispersive wave emission in a gas-filled hollow-core fiber waveguide. The light source allows tuning from ~340 nm to 465 nm (645 THz to ~885 THz) with conversion efficiencies of 1.5 %. Ultra-broadband absorption spectroscopy is demonstrated by studying nitrogen dioxide, a molecular species of major atmospheric relevance strongly absorbing across the ultraviolet and visible spectral region. We show that the coherence of the 80 MHz ytterbium fiber-based frequency comb seeding the frequency up-conversion process is conserved, paving the way toward further ultra-broadband (dual) comb spectroscopy across the ultraviolet/visible range.