Octave-wide broadening of ultraviolet dispersive wave driven by soliton-splitting dynamics

TL;DR

This paper demonstrates a novel soliton dynamic regime that efficiently generates an octave-wide ultraviolet dispersive wave spectrum through soliton-splitting effects and high-order dispersion in a simple fiber setup.

Contribution

It uncovers a new regime of soliton dynamics where pulse splitting enhances ultraviolet dispersive wave broadening, enabling efficient octave-wide spectrum generation.

Findings

Octave-wide ultraviolet spectrum achieved from simple capillary fiber setup.

High-efficiency dispersive wave generation via soliton-splitting dynamics.

Broad spectrum covering 200-400 nm useful for spectroscopy and metrology.

Abstract

Coherent dispersive wave emission, as an important phenomenon of soliton dynamics, manifests itself in multiple platforms of nonlinear optics from fibre waveguides to integrated photonics. Limited by its resonance nature, efficient generation of coherent dispersive wave with ultra-broad bandwidth has, however, proved difficult to realize. Here, we unveil a new regime of soliton dynamics in which the dispersive wave emission process strongly couples with the splitting dynamics of the driving pulse. High-order dispersion and self-steepening effects, accumulated over soliton self-compression, break the system symmetry, giving rise to high-efficiency generation of coherent dispersive wave in the ultraviolet region. Simultaneously, asymmetric soliton splitting results in the appearance of a temporally-delayed ultrashort pulse with high intensity, overlapping and copropagating with the dispersive wave pulse. Intense cross-phase modulations lead to octave-wide broadening of the dispersive wave spectrum, covering 200 to 400 nm wavelengths. The highly-coherent, octave-wide ultraviolet spectrum, generated from the simple capillary fibre set-up, is in great demand for time-resolved spectroscopy, ultrafast electron microscopy and frequency metrology applications, and the critical role of the secondary pulse in this process reveals some new opportunities for all-optical control of versatile soliton dynamics.