Experimental and theoretical study of the passively mode-locked   Ytterbium-doped double-clad fiber laser
  We consider an Yb-doped double-clad fiber laser in a unidirectional ring cavity containing a polarizer placed between two half-wave plates. Depending on the orientation of the phase plates, the laser operates in continuous, Q-switch, mode-lock or unstable self-pulsing regime. An experimental study of the stability of the mode locking regime is realized versus the orientation of the half-wave plates. A model for the stability of self-mode-locking and cw operation is developed starting from two coupled nonlinear Schrodinger equations in a gain medium. The model is reduced to a master equation in which the coefficients are explicitly dependent on the orientation angles of the phase plates. Analytical solutions are given together with their stability versus the angles. 
Herve Leblond (LPOMA), Mohamed Salhi (LPOMA), Ammar Hideur (GOO,   CORIA), Thierry Chartier (GOO, CORIA), Marc Brunel (GOO, ...