Polarization controlled multi-wavelength Er-doped fiber laser using fiber Bragg grating written in few-mode side-hole fiber with an elliptical core.

We propose and experimentally demonstrate a novel method for multi-wavelength erbium-doped fiber laser by using fiber Bragg gratings written in few-mode side-hole fiber with an elliptical core. The resonance peaks can be made to split by properly adjusting the polarization state due to the high birefringence of the fiber with the elliptical core. The number of lasing wavelengths can thus be switched using the polarization controller. This multi-wavelength laser has the advantages of low cost, novel and simple configuration.