Investigation On Nonlinear Dynamics Of 1550nm Vertical-Cavity Surface-Emitting Lasers Subject To Optoelectronic Feedback

Semiconductor lasers subject to optical feedback,optical injection or optoelectronic feedback can generate rich nonlinear dynamical behaviors such as Period-one(P1),stable injection locking(SIL),Quasiperiodic Pulsing(QP),and chaos(CO).These nonlinear dynamical behaviors have great potential applications in the fields of microwave photonics,random number generation,chaotic secure communication,neuro photonics etc.Compared with conventional Edge-Emitting Semiconductor Lasers(EELs),Vertical-Cavity Surface-Emitting Lasers(VCSELs)has become a focus because of its unique advantages such as low threshold current,small volume,small far field divergence angle,low fiber coupling loss,single-longitudinal-mode output and easy integration into large-scale circuit.Especially,the long wavelength(1310nm-1550nm)VCSELs,which corresponds to the optical fiber communication window,has attracted considerable attention in recent years because of the wavelength compatibility with commercial fiber systems.Previous works on the nonlinear dynamic characteristics of VCSELs is mainly focused on the cases of optical feedback and optical injection,and related reports on the nonlinear dynamics of VCSELs subject to photoelectric feedback are mostly theoretical results,while the experimental reports are relatively scarce.Therefore,the experimental investigation on the nonlinear dynamics of 1550 nm VCSELs subject to photoelectric feedback has great practical significance.In this paper,the nonlinear dynamics of 1550 nm VCSELs under positive optoelectronic feedback and negative optoelectronic feedback are experimentally investigated,and the evolution path of these dynamical states is analyzed.The results show that,for a fixed positive or negative optoelectronic feedback strength,1550 nm-VCSEL can exhibit rich nonlinear dynamic states such as Regular Pulsing(RP),Quasiperiodic Pulsing(QP),and Chaotic Pulsing(CP)under different bias currents.On the other hand,for a fixed bias current,through adjusting the positive or negative optoelectronic feedback strength,diverse dynamical states can also be observed in 1550 nm VCSEL.For the case of positive optoelectronic feedback,the 1550 nm VCSEL operates at stable state(S)under the small bias current and weak positive optoelectronic feedback strength.Within a higher bias current range,the dynamical behaviors of the laser follow a repeated RP-QP-RP route with increasing the photoelectric positive feedback strength.For the case of negative optoelectronic feedback,the laser also works at stable state under the small bias current and weak negative optoelectronic feedback.With increasing the bias current,the dynamical behaviors usually follow a repeated RP-QP-RP route to CP state with increasing optoelectronic feedback strength.When the bias current is increased to a certain level,the dynamical behaviors of 1550 nm VCSEL follow a repeated RP-QP-CP route with the increase of negative optoelectronic feedback strength.In addition,the mappings of nonlinear dynamical behaviors in a 1550 nm VCSEL subject to different optoelectronic feedback was given in the parameter space of bias current and feedback strength.