Mechanism for stable, ultra-flat multiwavelength operation in erbium-doped fiber lasers employing intensity-dependent loss

We study a mechanism to attain stable and ultra-flat multiwavelength oscillations in erbium-doped fiber lasers (EDFLs). The key concept is to introduce intensity-dependent loss (IDL) into the laser cavity, which can effectively suppress the mode competition in the homogeneously broadened gain medium and ensure a uniform power distribution over wavelengths via the gain-clamping effect. The technique was successfully demonstrated by employing a nonlinear optical loop mirror (NOLM) in erbium-doped fiber laser cavity. Based on the experimental results, further experimental investigation and theoretical analysis are carried out to show the effectiveness of the gain-clamping mechanism in realizing the multiwavelength operation of the EDFL.

► Mechanism for multiwavelength fiber lasers employing intensity-dependent loss is studied. ► The analysis provides a better explanation to the experimental results obtained before. ► The analysis provides a general approach to achieve stable broadband multiwavelength lasers.