Multistable single-mode emission from solid-state lasers

The conditions for continuous stable single-mode emission are determined for a solid-state laser with a slow-response saturable absorber and a negative feedback loop. It is shown that nonlinear selective losses associated with a spatially inhomogeneous saturation of the absorber by a standing-wave field give rise to multistability. The frequency of cw monochromatic radiation established after the transient evolution stage depends on the initial lasing conditions. The results yield the parameters of the negative feedback loop necessary to ensure that the buildup of self-excited relaxation fluctuations in a solid-state laser (owing to the saturable absorber) is suppressed and single-mode continuous lasing is stabilised.