  We study the suppression of noise degradation in high-power soliton-induced
supercontinuum generation under the influence of plasma contributions in
metallic dielectric-coated hollow waveguides. The high coherence of the
supercontinuum is related to the coherent seed components formed by the
abruptly rising plasma density. We predict the generation of highly coherent
supercontinua with two-octave broad spectra and spectral power densities in the
range ofMW/nm in such waveguides.
