Flexible Attosecond Soliton Transients for Extreme Resolution

Introduction

Ultrafast laser pulses allow us to follow fundamental processes such as chemical reactions and electron transport at their natural timescale. Because optical (ultraviolet, visible or infrared) laser sources have not been able to reach the attosecond pulse duration required to investigate the fastest events, ultrafast science has moved to extreme-ultraviolet (XUV) wavelengths.

Challenges with XUV Spectroscopy

However, XUV photon energies are far higher than the scale of chemically and electronically relevant valence-electron excitations, so XUV spectroscopy is at most only indirectly sensitive to some of the most important interactions. Furthermore, the low pulse energy of attosecond XUV sources has so far prevented experiments with true attosecond time resolution.

Project Goals

In FASTER, I will push far beyond the limits of conventional laser sources and bring attosecond time resolution to the optical domain. Using advanced optical soliton dynamics in gas-filled hollow capillary fibres, I will create ultrabroadband supercontinuum probe pulses and wavelength-tuneable pump pulses from the vacuum ultraviolet (100 nm) to the near infrared (1000 nm) with both attosecond duration and sufficient pulse energy for attosecond pump-probe studies.

Methodology

Using the flexibility of soliton dynamics and all-optical spatio-spectral manipulation, I will tailor these pulses to specific experiments. I will then take one step further and develop two-dimensional spectroscopy with the same approach, combining ultrabroadband optical attosecond pulses with the ability to identify different excitation pathways and quantum coherences.

Collaboration and Applications

In collaboration with expert groups, I will apply these new capabilities to some of the most challenging questions in ultrafast science and directly observe crucial valence-electron interactions with unprecedented time resolution.

Conclusion

FASTER aims at the physical limit of optical ultrafast laser pulses and a new regime of ultrafast spectroscopy, opening up entirely new ways of observing the fastest processes in nature.