  Ultrafast laser sources in the far ultraviolet (100 nm to 300 nm) have been
the subject of intense experimental efforts for several decades, driven
primarily by the requirements of advanced experiments in ultrafast science.
Resonant dispersive wave emission from high-energy laser pulses undergoing
soliton self-compression in a gas-filled hollow capillary fibre promises to
meet several of these requirements for the first time, most importantly by
combining wide-ranging wavelength tuneability with the generation of extremely
short pulses. In this Perspective, we give an overview of this approach to
ultrafast far-ultraviolet sources, including its historical origin and
underlying physical mechanism, the state of the art and current challenges, and
our view of potential applications both within and beyond ultrafast science.
