Abstract

In addition to the well-known multimode instability predicted in Refs. 1 and 2, a homogeneously broadened laser can display another type of multimode unstable behavior stemming from a different physical origin. This new type of behavior is associated with the development of positive real parts in the phase eigenvalues of the linearized problem, and manifests itself through the competitive action of neighboring cavity modes as one varies the detuning parameter. This type of phase instability can be the cause of regular output pulsations or hysteretic behavior of the bistable type in the output intensity and in the laser operating frequency. In this presentation we discuss the theoretical background of the effect, identify the physical conditions that may support regular oscillations or bistability, and investigate the interplay between the amplitude instability of Refs. 1 and 2 and the present type of unstable behavior.

© 1985 Optical Society of America