We have developed broad-band laser sources which show a sharp edge in
their spectra and are particularly suitable for ''white-laser'' coolin
g of ions in storage rings. They allow for a very large velocity captu
re range by maintaining the same cooling rate allowed by the single mo
de lasers. A large fraction of the circulating ions are expected to be
cooled both in coasting and bunched beams. The device, which does not
use an active medium, can easily operate at any frequency from UV to
IR spectral region.