Six wavelength Raman fiber laser for C + L-band Raman amplification

Summary form only given. Reported here is the first six-wavelength Raman fiber laser whose power distribution can be controlled to provide broadband adjustable gain in the C and L telecommunications bands. Radiation at 1100 nm is injected into a cascaded Raman resonator (CRR) where successive Raman shifts generate radiation at 1347 nm. The radiation at 1347 nm is coupled to resonant cavities at the six lasing wavelengths; 1428, 1445, 1466, 1480, 1494 and 1508 nm. The resonant cavities are constructed with six broadband high reflectivity (/spl sim/99%) Bragg gratings and six adjustable-reflectivity voltage-controlled output couplers. Stokes radiation at 1347 nm provides Raman gain for lasing at all six cavity resonances. The shorter wavelength radiation provides additional gain to the longer wavelength spectral components. Hence, the spectral power distribution is dependent upon the power in any individual spectral component.