Absolute instabilities in lasers with host-induced nonlinearitiesand dispersion

摘要

We analyze the occurrence of absolute instabilities in lasers thatncontain a dispersive host material with third-order nonlinearities.nStarting from the Maxwell-Bloch equations, we derive general multimodenequations to distinguish between convective and absolute instabilities.nWe find that both self-phase modulation and intensity-dependentnabsorption can dramatically affect the absolute stability of suchnlasers. In particular, the self-pulsing threshold (the so-called secondnlaser threshold) can occur at few times the first laser threshold evennin good-cavity lasers for which no self-pulsing occurs in the absence ofnintensity-dependent absorption