Tunable multi-wavelength all-fiber Raman source using fiber Sagnac loop filter

A multi-wavelength source is demonstrated in a cascaded-Raman fiber ring laser configuration using a tunable dual-section high birefringence fiber Sagnac loop filter. Depending on the pump powers and the cavity configurations, the source operates in the different wavelength regime between the 1120 and 1580 nm via cascaded Raman Stokes generation. The source generate up to 20 wavelength channels within the different orders of Raman Stokes wave regime with 0.4 nm channel spacing. The channel separation and the absolute wavelength of the multi-wavelength output are tunable and we show a discrete wavelength spacing of multi-wavelength output from 0.4 to 3 nm and continuous wavelength tuning over the wavelength channel spacing. (C) 2003 Elsevier Science B.V. All rights reserved.