  In this Letter we theoretically study a novel approach for soliton-induced
supercontinuum generation based on the application of metallic
dielectric-coated hollow waveguides. Low loss of such waveguides permits the
use of smaller diameters with enhanced dispersion control and enables the
generation of two-octave-broad spectra with unprecedentedly high spectral peak
power densities up to five orders of magnitude larger than in standard PCFs
with high coherence. We also predict that high-power supercontinua in the
vacuum ultraviolet can be generated in such waveguides.
