Photoionization-induced broadband dispersive wave generated in an Ar-filled hollow-core photonic crystal fiber

TL;DR

This paper demonstrates that plasma-driven blueshifting solitons in Ar-filled hollow-core photonic crystal fibers can significantly broaden dispersive wave spectra, enabling ultrafast pulse generation with potential applications in ultrafast optics.

Contribution

It reveals how plasma effects induce spectral broadening of dispersive waves in gas-filled HC-PCFs, advancing understanding of phase-matched DW generation mechanisms.

Findings

Spectral width of dispersive waves can be broadened via plasma-driven blueshifting.

Multiple spectral peaks of DW correspond to different fiber positions.

DW pulses can be compressed to ~29 fs with chirp compensation.

Abstract

The resonance band in hollow-core photonic crystal fiber (HC-PCF), while leading to high-loss region in the fiber transmission spectrum, has been successfully used for generating phase-matched dispersive wave (DW). Here, we report that the spectral width of the resonance-induced DW can be largely broadened due to plasma-driven blueshifting soliton. In the experiment, we observed that in a short length of Ar-filled single-ring HC-PCF the soliton self-compression and photoionization effects caused a strong spectral blueshift of the pump pulse, changing the phase-matching condition of the DW emission process. Therefore, broadening of DW spectrum to the longer-wavelength side was obtained with several spectral peaks, which correspond to the generation of DW at different positions along the fiber. In the simulation, we used super-Gauss windows with different central wavelengths to filter out these DW spectral peaks, and studied the time-domain characteristics of these peaks respectively using Fourier transform method. The simulation results verified that these multiple-peaks on the DW spectrum have different delays in the time domain, agreeing well with our theoretical prediction. Remarkably, we found that the whole time-domain DW trace can be compressed to ~29 fs using proper chirp compensation. The experimental and numerical results reported here provide some insight into the resonance-induced DW generation process in gas-filled HC-PCFs, they could also pave the way to ultrafast pulse generation using DW-emission mechanism.