Multi-wavelength Raman fiber laser with 2- and 3-stage cavities in a phosphosilicate fiber

We report on the simultaneous Raman lasing of three wavelengths at 1428/1454/1495 nm in a single P-doped optical fiber, by use of the stimulated Raman scattering of both P2O5 and SiO2/GeO2. The laser is formed with fiber Bragg grating cavities and the destination laser wavelengths are obtained through respective two- and three-stage Raman cascading processes for efficient wavelength conversion. Thermally controllable power ratios between the wavelengths have been realized by temperature detuning the most efficient 2-stage resonant wavelength at 1495 nm. With a comparable power level at each wavelength, the maximum total power achieved in our multi-wavelength Raman laser is 2.87 W in a fiber length of 700 m pumped with a 20 W double clad Yb fiber laser.