Current- and Feedback-Induced State Bistability in a 1550 nm-VCSEL With Negative Optoelectronic Feedback

We investigate experimentally the state bistability driven by current or feedback in a 1550 nm vertical-cavity surface-emitting laser (1550 nm-VCSEL) with negative optoelectronic feedback (NOEF). The results show that through continuously varying the controlled parameters such as the bias current or the feedback strength along different routes, under a set of given system parameters, there may exist two kinds of output states, i.e., state bistability, which are critically dependent on the history of how the controlled parameters are varied to reach the given values. Within the varied range of bias current or feedback strength, the state bistability is shown via the time series, power spectrum, and phase portrait of the output signal, and the physical mechanisms for the state bistability appearing in the NOEF 1550 nm-VCSEL are analyzed. Furthermore, the complexities of the corresponding states are evaluated by calculating the characteristic value of the normalized permutation entropy of the output from the NOEF 1550 nm-VCSEL. Additionally, by revealing the evolution of the dynamical states under the increase and decrease in the controlled parameters, the ranges of the parameters required for generating current-induced or feedback-induced state bistability can be specified to certain degree.