  We describe a tunable low-energy photon source consisting of a laser-driven
xenon plasma lamp coupled to a Czerny-Turner monochromator. The combined
tunability, brightness, and narrow spectral bandwidth make this light source
useful in laboratory-based high-resolution photoemission spectroscopy
experiments. The source supplies photons with energies up to ~7 eV, delivering
under typical conditions >10^12 ph/s within a 10 meV spectral bandwidth, which
is comparable to helium plasma lamps and many synchrotron beamlines. We first
describe the lamp and monochromator system and then characterize its output,
with attention to those parameters which are of interest for photoemission
experiments. Finally, we present angle-resolved photoemission spectroscopy data
using the light source and compare its performance to a conventional helium
plasma lamp.
