Dynamics of an erbium-doped fiber laser with pump modulation: Theory and experiment

We study in detail the complex dynamics of an erbium-doped fiber laser that has been subjected to harmonic modulation of a diode pump laser. We introduce a novel laser model that describes perfectly all experimentally observed features. The model is generalized to a nonlinear oscillator. The coexistence of different periodic and chaotic regimes and their relation to subharmonics and higher harmonics of the relaxation oscillation frequency of the laser are demonstrated with codimensional-one and codimensional-two bifurcation diagrams in parameter space of the modulation frequency and amplitude. The phase difference between the laser response and the pump modulation is also investigated. � 2005 Optical Society of America