Field-resolved attosecond solitons

Abstract

Here we harness soliton dynamics in a hollow-core fibre to generate attosecond laser pulses spanning the deep ultraviolet (DUV) to the near infrared, and we record their electric-field waveforms using nonlinear photoconductive sampling. By combining these techniques, we measure ultrashort pulses containing a soliton at optical wavelengths and generated a resonant dispersive wave covering the DUV regime with a total pulse duration of 350 attoseconds full width at half maximum of the squared field, demonstrating the extension of the electric-field sampling bandwidth to ultrashort wavelengths. Therefore, we provide a flexible and efficient route to the generation of intense isolated attosecond pulses complementary to those based on high-harmonic generation in gases, in a spectral range particularly interesting for studies in solids and in molecules. Finally, we show that these subcycle DUV–near-infrared pulses provide sufficient intensities to ionize argon and, thus, access attosecond strong-field laser physics in these spectral regions.