Chaotic signal dynamics of VCSEL for secure optical communication

Abstract

In this paper, the influence of the rotating polarization angle of optical feedback (OF) on the chaotic dynamic behavior of vertical-cavity surface-emitting lasers (VCSELs) is studied numerically. Parallel-polarization optical feedback (PPOF) is considered in this investigation. A numerical model using Simulink is implemented for the polarization resolved of a VCSEL with PPOF using a Lang-Kobayashi model. The trajectory attractors and correlation function are used to evaluate the chaotic dynamics and measure the chaotic synchronization between the orthogonal polarization modes (XP) and (YP) of the VCSEL. It is shown that a high-quality polarization-resolved chaos synchronization is achieved in the VCSEL when it is subjected to the rotated-polarization angle with strong OF. The results are displayed a poor dynamics synchronization between the XP and YP modes under the weak OF. However, the chaotic dynamic synchronization and polarization mode hopping are clearly observed at the high level of OF with 90o polarization rotated. The quality of chaotic synchronization improves with an increase of the polarization angle. This provides a new tool for secure optical communications system.