About possibility of bistable dynamics in lasers with single-mode cavities

Abstract

A previously unknown mechanism of bistable behavior in lasers with single-mode cavities is proposed and analyzed. It is shown that if losses in a cavity exhibit nonmonotonic dependence on frequency, the equation for stationary lasing frequencies can have multiple solutions even in single-mode cavities. In such a case, a system can generate one of several lasing outputs characterized by different frequencies and intensities. All these potential lasing states are stable at the same pumping level, and the choice between them is determined by initial conditions. The latter can be, in principle, controlled by seeding pulses. This mechanism does not depend on such nonlinear effects responsible for most known types of bistability as saturable absorption or cross saturation. An example of a cavity structure, in which such a mechanism can be realized, is presented. Standard lasing equations fail to describe dynamical behavior of such systems; therefore a generalized approach treating dynamic of lasing frequency and intensity on equal footing is developed.