SELF-PULSING LASING WITHOUT INVERSION IN THE DOUBLE-LAMBDA SCHEME

Lasing without inversion (LWI) is investigated from a nonlinear dynami cs point of view for an atomic system with three coupled J = 0.1 trans itions. The driving and generated fields couple two of these transitio ns defining a double-Lambda scheme. In addition, two incoherent pump f ields are acting on the system. We find hat LWI can occur not only in a continuous wave regime but also in a self-pulsing regime. A clear ph ysical interpretation of the origin of this self-pulsing LWI is given. We obtain analytically the threshold driving field intensity needed t o achieve both continuous wave and self-pulsing LWI emission. For larg e enough cavity losses, the system can reach either continuous wave or self-pulsing regimes by only changing the driving field intensity.