Modeling and Analysis of a Pulsed Er-Tm Fiber Laser System

A theoretical model concerning a double-cavity, pulsed, dual-wavelength Er-Tm fiber laser is built. In this laser system, saturation induced passive Q-switching of an Er-doped fiber laser and resonantly pumped gain-switching of a Tm-doped fiber laser are realized simultaneously. Related population transitions of the passive Q-switching and gain-switching processes in this laser system are described. Characteristics of the Er-Tm fiber laser are investigated and discussed with different pump powers and cavity reflectivities. Numerical results indicate that this double-cavity laser configuration shortens the lifetime and improves the maximum recovery ratio of the saturable absorber at high repetition rate.