Physics and Applications of Laser Diode Chaos

An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic

Delay coupling enhances synchronization in complex networks

The phenomenon of enhancement of synchronization due to time delay is investigated in an arbitrary delay coupled network with chaotic units. Using the master stability formalism for a delay coupled network, we elaborate that there always exists an extended regime of stable synchronous solutions of the network for appropriate coupling delays. Further, the stable synchronous state is achieved even at smaller values of coupling strength with delay, which can be only attained at much larger coupling strength without delay. This also facilitates the increase in the number of synchronized nodes in the delay coupled network beyond size instability of the same network without delay. Further, the largest transverse Lyapunov exponents in the master stability surface of the network clearly demarcates the stable synchronous solutions from the unstable ones. The generic nature of our results is also corroborated using three paradigmatic models, namely, Rössler and Lorenz systems as well as Hindmarsh-Rose neurons as nodes in the delay coupled network