Abstract: To examine the chaotic dynamics and its application in communication of a unidirectionally coupled vertical-cavity surface-emitting laser (VCSEL) system,the synchronization performance of polarization modes of two unidirectionally coupled VCSELs were simulated.An encryption scheme was proposed,where the phases of the polarization states of the master laser were modulated.It was demonstrated that high synchronization could be achieved between corresponding polarization components of the master laser and the slave laser.Moreover,there were two distinct synchronization regimes,i.e.complete synchronization and injection locking synchronization.The transmitted digital information was successfully recovered at each polarization branch of the slaver laser.The results open an opportunity for multichannel chaotic communication by utilizing different polarization components in single-mode or multi-transverse-mode VCSELs.