  A recently developed source of ultraviolet radiation, based on optical
soliton propagation in a gas-filled hollow-core photonic crystal fiber, is
applied here to angle-resolved photoemission spectroscopy (ARPES).
Near-infrared femtosecond pulses of only few {\mu}J energy generate vacuum
ultraviolet (VUV) radiation between 5.5 and 9 eV inside the gas-filled fiber.
These pulses are used to measure the band structure of the topological
insulator Bi2Se3 with a signal to noise ratio comparable to that obtained with
high order harmonics from a gas jet. The two-order-of-magnitude gain in
efficiency promises time-resolved ARPES measurements at repetition rates of
hundreds of kHz or even MHz, with photon energies that cover the first
Brillouin zone of most materials.
