A new classification for optical instabilities

The authors propose a new scheme for the classification of the optical instabilities that emerge within the framework of the Maxwell-Bloch model. The scheme is based on an appropriate extension of the notions of amplitude and phase instability advanced in earlier publications and generalized in this work to include the free running laser, optical bistability and the laser with an injected signal. They address their considerations to a unidirectional ring cavity model, in the plane wave approximation and with a homogeneously broadened, two-level active medium