The stationary properties of a single-mode laser with positive and negative
correlations between additive and multiplicative white-noise terms are inv
estigated. By virtue of a simple rule and decoupling ansatz, the intensity
correlation function and correlation time for the laser model are derived.
We found that: (1) the fluctuation of light intensity with negative correla
tions between the noise terms are reduced in comparison with those for posi
tive correlations; (2) the coupling between additive and multiplicative noi
ses enhances the rate of decay of intensity correlation; (3) the effects of
negative correlations between the noise terms are more remarkable than tho
se of positive correlations.