Dynamics of a vectorial neodymium-doped fibre laser passively Q switched by a polymer-based saturable absorber

Abstract

We report the dynamic regimes obtained in a bipolarized neodymium-doped fibre laser self Q switched by a thin slice of a polymerbased saturable absorber. We demonstrate the influence of the total losses and of the anisotropic losses induced by defocusing the saturable absorber and by tilting the cavity mirror, respectively. Starting from a global chaotic behaviour for low-loss configuration, the system evolves toward an n-periodic (n = 4, 2 and 1) regime for increasing losses. Stabilization of these regimes depends on the anisotropic losses. Conversely, when cavity mirrors are tilted alone, an additional regime such as intermittence is obtained. All these regimes have been identified as due to nonlinear coupling through the saturable absorber between two distinct polarized modes. These modes have been experimentally resolved.