Synchronized chaotic mode hopping in DBR lasers with delayed opto-electricfeedback

We propose and demonstrate a scheme for generating synchronized chaotic mod e hopping in two wavelength-tunable lasers, Chaotic mode hopping resulting in large hops in wavelength is induced by delayed feedback of an electrical signal proportional to the intensity of the laser output which passes thro ugh an optical filter. Mode hopping among up to 11 modes was experimentally observed and optical signals in each wavelength band show a different on-o ff modulation time series. Analysis of the time series indicates high dimen sionality. By using a unidirectional coupling method that injects part of t he output of one laser into another, we can synchronize the chaotic mode ho pping of two separate lasers and obtain synchronized chaotic on-off modulat ion patterns in multiple corresponding wavelength bands. The robustness of the synchronization with respect to the parameter mismatch and the effects of the coupling strength are investigated. The chaotic mode hopping dynamic s and synchronization are well described with a numerical model that includ es the characteristics of the laser tuning and the filter transmission. A m ultiplexed data transmission scheme using chaotic carriers is proposed and experiments demonstrate that multiple messages can be simultaneously recove red when chaos synchronization is achieved.