PUMP MODULATION OF A 2-MODE FABRY-PEROT LASER - INFLUENCE OF AN INTERNAL RESONANCE

We study the response of a two-mode laser to an external periodic pump modulation of small amplitude, The control parameters are the pump-mo dulation frequency and amplitude. We first show that the ratio of the two relaxation oscillation frequencies may be commensurate. We then in vestigate the parameter domain in which the lowest of the two relaxati on oscillation frequencies is close to half the other relaxation oscil lation frequency. We derive analytically a pair of nonlinear amplitude equations for the dynamical modes of the system. This gives access to the stability of the time-periodic solutions that oscillate at the pu mp-modulation frequency and its first (sub)harmonic. It also determine s the occurrence of secondary bifurcations leading to mon complex solu tions.