Theoretical model for coupled solid-state lasers - art. no. 033814

We consider the theoretical description of two parallel and adjacent lasers in a monolitic crystal. Starting from first principles, a semiclassical th eory is developed. A system of nonlinear differential equations for both la sers field and inversion is obtained. In the weak-coupling limit, we show t hat the coupling between the laser fields is linear. Moreover, the coupling strength is measured by a complex coefficient: (i) the real part is relate d to the overlap of fields with a weight given by the pump beam profile, wh ile (ii) the, imaginary part is associated with the refractive index struct ure created inside the crystal. The parameters are defined explicitly in te rms of pump, index, and "cavity eigenmodes" structures. The resulting syste m of two coupled nonlinear oscillators is analyzed. The effect of this coup ling on the laser's dynamical behaviors, like stable synchronization and be ating phenomena, is studied.