Synchronization of Chaotic Intensities and Phases in an Array of N Lasers

A linear array of N mutually coupled single-mode lasers is investigated. It is shown that the intensities of N lasers are chaotically synchronized when the coupling between lasers isrelatively strong. The chaotic synchronization of intensitiesdepends on the location of the lasers in the array. The chaoticsynchronization appears between two outmost lasers, the secondtwo outmost lasers, etc. There is no synchronization betweennearest neighbors of the lasers. If the number of N is odd, themiddle laser is never synchronized between any lasers. The chaoticsynchronization of phases between nearest lasers in the array isexamined by using the analytic signal and the Gaussian filtermethods based on the peak of the power spectrum of the intensity.It can be seen that the message of chaotic intensitysynchronization is conveyed through the phase synchronization.