Time delay signature concealment of chaotic output in a master-slave vertical-cavity surface-emitting lasers system

The concealment of time-delay (TD) signature in a master-slave vertical-cavity surface-emitting laser (VCSEL) system has been investigated numerically. The system is composed of a slave vertical-cavity surface-emitting laser (S-VCSEL) subject to dual-path polarization-preserved optical injection (DP-PPOI) from a master VCSEL (M-VCSEL) with double-cavity polarization-preserved optical feedback (DC-PPOF). The results show that the TD signature can be effectively concealed by selecting appropriate operation parameters such as external cavity length, injection rate and frequency detuning. Furthermore, in comparison with two other VCSEL configurations, the configuration of a S-VCSEL subject to DP-PPOI from a M-VCSEL with DC-PPOF shows superior suppression of the TD signature under the same conditions.