Irreversible circulation and the undamped spiking in lasers

Our new theory of fluctuation was applied to the undamped spiking in lasers with single mode saturable absorption. At the marginal points, which lead to limit cycles, it was found that the irreversible circulation α and the residual circulation α′ diverge together with the variance σ. The model system of this article has effectively three degrees of freedom; however, it was demonstrated that the dominant motion and the fluctuation have two dimensional character in the neighbourhood of a hard mode instability.