Many important breakthroughs in science have occurred when investigating the laws of nature at extremes. Strong-field effects, such as relativistic plasma dynamics, high-harmonic generation and laser-driven particle acceleration, appear at extreme intensities of electromagnetic fields. By using very short laser pulses and focusing them very tightly, these effects and their applications come within reach of table-top systems. The aim of this project it to explore extreme strong-field physics at the fundamental limits of spatio-temporal confinement and open the door to a completely new regime of strong-field interactions in the vacuum ultraviolet. The core methodology is to scale scaling soliton-driven light sources in hollow capillary fibres by two orders of magnitude in power compared to the state of the art. In this way, we aim to create optical attosecond pulses (sub-cycle electric field transients in the visible part of the electromagnetic spectrum) with multi-terawatt peak power and excellent pulse contrast, with homogeneous linear polarisation, circular polarisation, or as radial vector beams. The latter can be focused to sub-wavelength spot sizes and create a relativistic electric field in the longitudinal direction. In combination with the sub-cycle duration, this will be a completely unique driving pulse for plasma physics and particle acceleration. We will use these pulses for the generation of high-energy isolated extreme ultraviolet and X-ray attosecond pulses from plasma mirrors and for the creation of isolated multi-MeV attosecond electron bunches using in-vacuum strong-field electron acceleration, both in a compact table-top system. We will also generate few-femtosecond pulses tuneable across the vacuum ultraviolet (100 nm to 200 nm) with up to 300 GW peak power, opening the door to a regime of ultraviolet-driven strong-field and relativistic nonlinear effects in both gases and plasmas that has been almost entirely inaccessible, and hence unexplored.
The importance of the high-brightness and ultrafast far-ultraviolet, X-ray and electron sources that will be developed in this project comes from their application to basic discovery science: investigations of biological function and chemical reactions—enabling us to make new drugs, develop new chemical syntheses, and understand disease; investigations into the structure and dynamics of condensed matter—leading to the development of new materials, electronics, and devices for use in modern society; and fundamental physics—leading to new technology.
