Deep-UV to mid-IR supercontinuum generation driven by mid-IR ultrashort pulses in a gas-filled fiber

TL;DR

This paper demonstrates multi-octave supercontinuum generation from deep-UV to mid-IR using a gas-filled hollow-core fiber driven by ultrashort pulses, revealing soliton-plasma dynamics as the key mechanism.

Contribution

It reports the first multi-octave supercontinuum spanning from 200 nm to 4000 nm in a gas-filled fiber, highlighting soliton-plasma interactions for spectral broadening.

Findings

Achieved 5 mW average power output with ~100 fs pulses.

Generated a strong dispersive wave at 275 nm with 28.4% of total energy.

Showed how pump energy and gas pressure influence supercontinuum generation.

Abstract

Supercontinuum (SC) generation based on ultrashort pulse compression constitutes one of the most promising technologies towards an ultra-wide bandwidth, high-brightness and spatially coherent light sources for applications such as spectroscopy and microscopy. Here, multi-octave SC generation in a gas-filled hollow-core antiresonant fiber (HC-ARF) is reported spanning from 200 nm in the deep ultraviolet (DUV) to 4000 nm in the mid-infrared (mid-IR). A measured average output power of 5 mW was obtained by pumping at the center wavelength of the first anti-resonance transmission window (2460 nm) with ~100 fs pulses and an injected pulse energy of ~7-8 {\mu}J. The mechanism behind the extreme spectral broadening relies upon intense soliton-plasma nonlinear dynamics which leads to efficient soliton self-compression and phase-matched dispersive wave (DW) emission in the DUV region. The strongest DW is observed at 275 nm having an estimated pulse energy of 1.42 {\mu}J, corresponding to 28.4 % of the total output energy. Furthermore, the effect of changing the pump pulse energy and gas pressure on the nonlinear dynamics and their direct impact on SC generation was investigated. The current work paves a new way towards novel investigations of gas-based ultrafast nonlinear optics in the emerging mid-IR spectral regime.