Maxwell-Bloch approach to excess quantum noise

To meet recent experimental advances, we generalize the intuitively appeali ng nonorthogonal-mode theory of excess quantum noise by introducing a Maxwe ll-Bloch description of the gain medium. The resulting equations extend the nonorthogonal-mode approach beyond the class A linear-gain regime providin g a general starting point for theoretical descriptions of excess quantum n oise. As an illustration of our theory, we derive rate equations describing excess quantum noise in class B lasers and obtain the non-lorentzian spect rum due to the coloring of excess noise in class A lasers accounting for ga in saturation. [S1050-2947(99)03106-6].