ONE-DIMENSIONAL MODEL OF A SINGLE-MODE LASER WITH CORRELATION BETWEENADDITIVE AND MULTIPLICATIVE NOISES

Recently, Zhu [Phys. Rev. A 47 (1993) 2405] and Jia ei al. [Phys. Rev. A 51 (1995) 3196] investigated the statistical properties of a single -mode laser with correlation between additive and multiplicative noise s by using a one-dimensional model with a one-dimensional Langevin equ ation of the single-mode laser derived by Fox et al. [Phys. Rev. A 35 (1987) 1838], We point out that this one-dimensional model, whose Lang evin equation was obtained under the assumption that the noises are un correlated, is not always stochastically equivalent to the single-mode cubic laser model when additive and multiplicative noises are correla ted, As a modification, a general model which is stochastically equiva lent to the cubic model of a single-mode laser driven by correlated no ises is derived. Based on this, a different one-dimensional model is g iven in the case where the former one used by Zhu and Jia et al, is no t suitable.