Quantum theory of bistable inversionless lasers

A fully quantum-mechanical theory of bistable inversionless lasers is devel oped by generalizing the Scully-Lamb laser theory to this kind of laser sys tems. By converting the quantum master equation of the system into a Fokker -Planck equation, we obtain the steady-stare properties and the fluctuation properties of the laser field for both coherently and incoherently injecte d atomic systems. It is shown that both the intensity and phase fluctuation s of the laser system with coherent atomic injection are reduced correspond ing to their counterpart of the incoherent atomic injection. The phase nois e of bistable inversionless lasers can be quenched down to the vacuum-noise level for both atomic injections. [S1050-2947(98)00412-0].