A New High-Brightness Ultrafast Vacuum-Ultraviolet Light-Source


Optical soliton dynamics in a waveguide can cause the extreme alteration of the temporal and spectral shape of a propagating light pulse. They occur at watt to kilowatt peak power in glass-core optical fibres and up to the gigawatt level in gas-filled microstructured hollow-core fibres. We have demonstrated, for the first time, optical soliton dynamics in conventional large-core hollow capillary fibres. Our analysis and modelling show that this enables further scaling of soliton effects by several orders of magnitude to the multi-mJ energy and terawatt peak power level. We experimentally demonstrate two key soliton effects. First, we observe self-compression to sub-cycle pulses and infer the creation of sub-femtosecond field waveforms—a route to high-power optical attosecond pulse generation. Second, we efficiently generate continuously tunable high-energy (up to 16 μJ) pulses in the vacuum and deep ultraviolet spectral region (110 nm to 400 nm) through resonant dispersive-wave emission. These pulses are expected to have a duration of 2 fs. This new regime of high-energy ultrafast soliton effects promises to be the foundation of a new generation of table-top light sources for ultrafast strong-field physics and advanced spectroscopy.

Rutherford Appleton Laboratory, Oxfordshire, UK