Chaotic Behavior Associated with a Multicodimension Bifurcations in a Laser with a Saturable Absorber

It has been shown both theoretically and experimentally that a laser with a saturable absorber (LSA) may exhibit various types of chaotic behavior. Theoretical investigations of such behavior in LSA with CO2 amplifying medium has been carried out on the basis of three level : two level rate equation model [1]. In order to improve the agreement between the model and experimental observations the extension of the model including the polarization of molecular absorber has been proposed in Ref.[2]. It has been shown in [2] that a new types of chaotic regimes arise due to the time lag between the polarization and field. Here we show that these chaotic regimes are associated with a codimension- four bifurcation point. We present the detailed investigation of the bifurcation sequences leading to chaotic operations in the vicinity of this point in the case of detuned LSA.