Laser with Saturable Absorber. Fluctuations and Stability

Abstract

The development of laser theory has focused recently much of interest on the general description of instabilities in systems far from thermal equilibrium. It is well recognized now a-days that in physics, biophysics and chemistry one meets a variety of simple open systems which behave in astonishingly similar way as far as setting of temporal or spacial orders are concerned. The idea to treat all these systems on a common basis resembles the philosophy which achieved its great success in the equilibrium theory and eventually led to the general theory of phase transitions with its classes of universality etc. Though in the last decade much has been achieved along these lines, the nonequilibrium theory seems to be presently at the stage where the detailed description of microscopic models is highly desirable since they still unveil qualitatively new features which shall be incorporated into the general theory. One example of such not yet completely described and understood problems is the nature of higher order instabilities which sometime lead to strange erratic dynamics. Another one is the problem of imposing fluctuations on the semiclassical picture of instabilities.