Multiwavelength erbium-doped fiber laser based on a nonlinear amplifying loop mirror assisted by un-pumped EDF

A multiwavelength erbium-doped fiber (EDF) laser based on a nonlinear amplifying loop mirror (NALM) is proposed and experimentally demonstrated. The NALM provides intensity-dependent transmissivity to equalize different-wavelength powers and the transmission can be uniquely optimized by controlling the cavity loss associated with a section of un-pumped EDF, which also enhances the output signal-to-noise ratio (SNR). Through adjusting the polarization controllers (PCs), under only 70 mW pump power, up to 62-wavelength output with channel spacing of 0.45 nm has been achieved. Also, the lasing tunability and stability are verified.