Multiwavelength erbium-doped fiber laser based on nonlinear polarization rotation assisted by four-wave-mixing

We experimentally demonstrate a simple-structure but efficient multiwavelength erbium-doped fiber laser based on nonlinear polarization rotation assisted by four-wave-mixing (FWM). Based on the combination of these two nonlinear mechanisms contributing to intensity-dependent loss to alleviate mode competition, the stable multiwavelength operation at room temperature can be realized in a length of dispersion-shifted fiber. We achieved up to 38-wavelength generation with a spacing of similar to 0.4 nm in the laser. In addition, through tuning the birefringence fiber filter, the lasing wavelength can be accurately tuned in the free spectrum range. (c) 2009 Elsevier B.V. All rights reserved.