  Mean-field evolution equations for the exciton and photon populations and
polarizations (Bloch-Lamb equations) are written and numerically solved in
order to describe the dynamics of electronic states in a quantum dot coupled to
the photon field of a microcavity. The equations account for phase space
filling effects and Coulomb interactions among carriers, and include also (in a
phenomenological way) incoherent pumping of the quantum dot, photon losses
through the microcavity mirrors, and electron-hole population decay due to
spontaneous emission of the dot. When the dot may support more than one
electron-hole pair, asymptotic oscillatory states, with periods between 0.5 and
1.5 ps, are found almost for any values of the system parameters.
