Optical bistability in semiconductor microcavities in the nondegenerate   parametric oscillation regime: analogy with the optical parametric oscillator
  We report the observation of optical bistability in a microcavity pumped at the "magic angle". Experimental evidence is given in the form of a hysteresis cycle of the nonlinear emission as a function of the pump intensity or the position of the excitation spot. The results can be well understood with simple theoretical considerations that underline the fundamental analogy between our system and an optical parametric oscillator. 
A. Baas, J.-Ph. Karr, M. Romanelli, A. Bramati, E. Giacobino