Experimental investigation on the nonlinear dynamics of two mutually coupled 1550 nm multi-transverse-mode vertical-cavity surface-emitting lasers.

We experimentally investigate the nonlinear dynamics of two mutually coupled 1550 nm multi-transverse-mode vertical-cavity surface-emitting lasers (VCSELs). The results show that, through continuously varying the coupling coefficient, the Y-polarization fundamental transverse mode and the Y-polarization first-order transverse mode in both VCSELs can be driven into period one, period doubling, multi-period, and chaos states. When the two mutually coupled VCSELs are simultaneously operating in the periodic state, localized synchronizations between the corresponding modes are observed. Moreover, mappings of dynamical states for typical transverse modes of the two mutually coupled VCSELs in the parameter space of the frequency detuning and coupling coefficient are specified.

Numerical investigations on multi-channel wideband chaotic signal generation by a multi-transverse mode vertical-cavity surface-emitting laser subject to chaotic optical injection.

A multi-channel wideband chaotic signal generation scheme is proposed and numerically investigated based on a slave multi-transverse mode vertical-cavity surface-emitting laser (SL) subject to chaotic optical injection from a master multi-transverse mode vertical-cavity surface-emitting laser (ML) with optical feedback. Taking two low-order transverse modes, LP01 and LP11, as an example for numerical calculations, the simulated results show that under suitable optical feedback both the LP01 and LP11 modes (two-channel) of a ML can be driven into the chaotic states where their bandwidths are relatively narrow at a level about 8 GHz. Further injecting the two chaotic signals into a SL, for the case of the globally chaotic optical injection, the SL can output two-channel chaotic signals with wide bandwidths above 20 GHz under appropriate operation parameters. Moreover, the case of SL with mode-selective chaotic optical injection is also analyzed.

Prediction performance of reservoir computing system based on a semiconductor laser subject to double optical feedback and optical injection.

A reservoir computing (RC) system based on a semiconductor laser (SL) with double optical feedback and optical injection is proposed, and the prediction performance of such a system is numerically investigated via Santa Fe Time-Series Prediction task. The simulation results indicate that the RC system can yield a good prediction performance. Through optimizing some relevant operating parameters, ultra-fast information processing rates up to Gb/s level can be realized for the prediction error is below 3%.

Observation of additional delayed-time in chaos synchronization of uni-directionally coupled VCSELs.

We report an experimental and numerical investigation on the existence of additional delayed-time in chaos synchronization of two uni-directionally coupled vertical-cavity surface-emitting lasers (VCSELs) for the first time. Under a generalized synchronization scenario, we demonstrate that there exists an additional delayed-time in addition to the time-of-flight between the two coupled VCSELs. The cross-correlation function analysis has been used as a method to determine the coupling delay and synchronization quality between two uni-directionally coupled chaotic VCSELs. We show that the injection strength significantly influences the additional delayed-time, and the injection strength analysis eventually substantiates the existence of additional delayed-time between the coupled lasers in experiments. The experimental results are in accordance with the numerical results. Additionally, we numerically study the effect of laser's internal parameter mismatches on additional delayed-time and synchronization quality between the lasers.