Multiwavelength fiber laser using a novel in-fiber comb filter

Simultaneous multiple wavelength lasing is demonstrated using a novel in-fiber comb filter. The filter is based on a fiber Bragg grating asymmetrically located in a Sagnac loop. Two filters with four band-passes and five band-passes, respectively, were fabricated and applied to an erbium-doped fiber ring laser. Stable four-wavelength and five-wavelength laser operations have been demonstrated.