BIFURCATIONS OF RELAXATION OSCILLATIONS IN AN OPTICALLY INJECTED DIODE-LASER

A diode laser subject to optical injection is known to perform relaxat ion oscillations for certain values of amplitude and detuning of the i nput signal. To describe this, an averaged amplitude-phase equation wa s derived and studied by means of simulation by de Jagher er al. Here we analyse this model with tools from bifurcation theory. This allows us to give explicit formulae for the relevant bifurcations. In this wa y we find all regions of different dynamical behaviour of the injected laser when the amplitude of the relaxation oscillations is small. We show that the injected laser can exhibit motion on a torus, the stabil ity of which depends on the linewidth-enhancement factor alpha. The di sappearance of this torus goes along with chaotic dynamics. The validi ty of the present model is discussed.