A desired Nth-order Stokes output and zeroth-order Stokes pump input are seeded into a rare-earth doped amplifier where the power of the zeroth-order Stokes signal is amplified prior to both signals entering a Raman amplifier comprised of N−1 Raman resonators, each uniquely tuned to one of the N−1 Stokes orders, in various configurations to include one or more nested and/or in-series Raman resonators. The zeroth-order Stokes signal is converted to the Nth−1-order Stokes wavelength in steps and the power level of the Nth-order Stokes wavelength is amplified as the two signals propagate through the Raman resonators. Each Raman resonator includes a photosensitive Raman fiber located between a pair of Bragg gratings. The linewidths of the Stokes orders can be controlled by offsetting the reflectivity bandwidths of each pair of Bragg gratings respectively located in the Raman resonators.