Chaotic synchronization performances of two unidirectionally coupled VCSELs subject to negative optoelectronic feedback

Abstract

Based on the framework of the spin-flip model （SFM）, the synchronization performance of two unidirectionally coupled vertical-cavity surface emitting lasers （VCSELs） subject to negative optoelectronic feedback has been theoretically investigated. The results show that, with the increase of the feedback intensity, the laser output power displays two different chaos regions, i. e., singles-polarization mode region and mixed mode region. The polarized mode in the single mode region can achieve good synchronization, but sharply decline in the quality of synchronization close to the mixed mode region. Within the mixed-mode region, the continuity and quality of synchronization of polarized modes are not ideal. The fact that the synchronization quality of the mixed mode is worse than that of the single mode, is on the contrary to reported results based on optical feedback. The reason may be due to that negative optoelectronic feedback has induced the competion between the polarized modes. In addition, we have found changes in internal parameters have a great impact on the selection of two chaotic regions.