title: Synchronization of chaos due to linear response in optically driven semiconductor lasers.
abstract: This paper presents physical aspects on chaos synchronization in semiconductor lasers (SLs) by studying synchronization from a fundamental standpoint of driven damped oscillators. We investigate the simple configuration, a chaotic master SL with optical feedback and a solitary slave SL. The point we emphasize is that the slave laser is regarded as a damped oscillator with relaxation oscillation. Linear stability analysis demonstrates that strong injection can enhance the damping of the slave SL. Consequently, the slave SL can have broad and nearly flat spectral characteristics in its driven response, which is sufficient for covering the broadband chaotic driving signal from the master SL. Numerical simulations verify that the slave SL subject to such strong injection synchronizes well with the chaotic driving signal. We consider that the synchronization phenomenon results from a quasilinear driven response of the slave SL with the remarkable spectral characteristics. Moreover, we discuss this type of chaos synchronization in comparison to anticipating-chaos synchronization occurring in our case from conventional complete synchronization theories, and clarify the different physical aspects of the chaos synchronization scheme. We also show that our analysis agrees well with the earlier experiments that could not have been explained by complete synchronization theory.
authors.affiliation: Department of Electronic Engineering, The University of Electro-Communications, 1-5-1 Chofu-gaoka, Chofu-shi, Tokyo 182-8585, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Murakami