Pump- and temperature-induced repetition frequency response study in hybrid mode-locked erbium fiber laser with distributed polarizer

We report a study on pump- and temperature-induced repetition frequency response in hybrid mode-locked stretched-pulse erbium fiber laser with distributed polarizer. For the first time to the best of our knowledge, we have shown frequency-dependent loss (FDL) contribution to pump-induced repetition frequency response behavior. FDL originates from wavelength-dependent saturation of nonlinear polarization evolution (NPE) mechanism which is inherent to stretched-pulse regime of operation. We have proposed an analytical model adequately describing NPE influence on pump-induced repetition frequency response. As it is observed, NPE-induced contribution substantially dominates over other physical perturbations leading to strictly different pump-induced repetition frequency response behavior compared to erbium fiber soliton laser.