  Cascaded Raman lasers enable high powers at various wavelength bands
inaccessible with conventional rare-earth doped lasers. The input and output
wavelengths of conventional implementations are fixed by the constituent fiber
gratings necessary for cascaded Raman conversion. We demonstrate here, a simple
architecture for high power, fixed and wavelength tunable, grating-free,
cascaded Raman conversion between different wavelength bands. The architecture
is based on the recently proposed distributed feedback Raman lasers. Here, we
implement a module which converts the Ytterbium band to the eye-safe 1.5micron
region. We demonstrate pump-limited output powers of over 30W in fixed and
continuously wavelength tunable configurations.
