Observation of Higher Order Dynamical States of a Homogeneously Broadened Laser

A series of new stable operating states of a homogeneously broadened laser have been observed. As the pump power is varied, thresholds are reached where the power and spectrum of the laser change discontinuously. In these states the laser simultaneously oscillates at two frequencies whose separation is given by the Rabi frequency or one of its subharmonics. A theoretical explanation is given which includes field-induced structure within the homogeneous line.