Multiwavelength erbium-doped fiber laser based on intensity-dependent transmission in a linear cavity

A multiwavelength erbium-doped fiber laser with linear cavity configuration is proposed and demonstrated. A power-symmetric nonlinear optical loop mirror (NOLM) serves as the laser's output coupler and has an intensity-induced increase in transmission (IIT) that leads to higher cavity loss for oscillating wavelengths with higher power. The IIT feature of the NOLM suppresses the mode competition in the erbium-doped fiber and ensures stable multiwavelength operation at room temperature. Both the wavelength number and the output power of the laser can be flexibly controlled by adjusting the work state of the NOLM via a quarter wave plate and/or a polarization controller.