A stable and uniform-amplitude multi-wavelength erbium-doped fiber laser based on nonlinear polarization rotation and a polarization-maintaining fiber loop mirror

Abstract

We propose and demonstrate a stable and uniform-amplitude multi-wavelength erbium-doped fiber laser based on nonlinear polarization rotation and a polarization-maintaining fiber (PMF) loop mirror. The nonlinear polarization rotation (NPR) effect induces an intensity-dependent loss (IDL) to alleviate mode competition caused by homogeneous gain broadening of erbium-doped fiber (EDF) at room temperature. By adjusting the polarization controllers (PCs) carefully, up to twelve stable wavelengths with a side mode suppression ratio (SMSR) of 28.8 dB are achieved. The outputs have uniform amplitudes and the power fluctuation and wavelength shift for each lasing wavelength are smaller than 0.1 dB and 0.02 nm, respectively, in an hour.