UV soliton dynamics and Raman-enhanced supercontinuum generation in photonic crystal fiber

TL;DR

This paper demonstrates ultrafast ultraviolet pulse generation and supercontinuum in gas-filled hollow-core photonic crystal fibers, highlighting hydrogen's enhanced Raman gain for efficient broadband UV light production.

Contribution

It introduces a novel method for generating ultrafast UV pulses and supercontinuum in gas-filled HC-PCFs, emphasizing hydrogen's superior Raman enhancement over argon.

Findings

Achieved sub-6-fs pulses from 400 nm with low energy (~500 nJ).

Generated a broad supercontinuum from deep UV to visible.

Hydrogen-filled fibers outperform argon in Raman-enhanced UV generation.

Abstract

Ultrafast broadband ultraviolet radiation is of importance in spectroscopy and photochemistry, since high photon energies enable single-photon excitations and ultrashort pulses allow time-resolved studies. Here we report the use of gas-filled hollow-core photonic crystal fibers (HC-PCFs) for efficient ultrafast nonlinear optics in the ultraviolet. Soliton self-compression of 400 nm pulses of (unprecedentedly low) ~500 nJ energies down to sub-6-fs durations is achieved, as well as resonant emission of tunable dispersive waves from these solitons. In addition, we discuss the generation of a flat supercontinuum extending from the deep ultraviolet to the visible in a hydrogen-filled HC-PCF. Comparisons with argon-filled fibers show that the enhanced Raman gain at high frequencies makes the hydrogen system more efficient. As HC-PCF technology develops, we expect these fiber-based ultraviolet sources to lead to new applications.