Electronic equivalent of a pump-modulated erbium-doped fiber laser

Abstract

We built the electronic equivalent circuit based on the model of a pump-modulated erbium-doped fiber laser. The model equations have two state variables, optical field intensity x and population inversion y, and a harmonic modulation applied to the pump parameter. In addition, the model contains two nonlinear terms, xy and ey. The exponential nonlinearity is implemented electronically using a power series expansion. The circuit dynamics is investigated using bifurcation, Lyapunov spectrum, and phase space analyses. Similar to the fiber laser, the equivalent electronic circuit exhibits very rich dynamics, exhibiting chaos and multiple coexisting periodic orbits. The existence of a saddle–node fixed point is demonstrated.