Multiwavelength switching of Raman fiber ring laser incorporating composite polarization-maintaining fiber Lyot-Sagnac filter

A multiwavelength switching laser is demonstrated by a precise and fast tuning of a composite Lyot-Sagnac comb filter based on multisegment polarization-maintaining fibers. Broadband multiwavelength output is generated by cascaded Raman Stokes waves between 1.12 and 1.58 microns in a fiber-ring cavity with a wave-division-multiplexed coupler. Theoretical and experimental analysis of stable multiwavelength output operation for various Raman gain fibers and the electro-optic switching and flexible space tuning of interleaved wavebands are performed.