Zero-lag intensity correlation properties in small ring laser network with heterogeneous delays

Abstract

The zero-lag correlation properties of intensity chaos in ring networks consisting of three semiconductor lasers mutually coupled with heterogeneous time delays are numerically investigated. The role of heterogeneous coupling delays with specific ratios on the zero-lag chaotic intensity correlation is revealed, and the effects of coupling rate, frequency detuning, and time delay heterogeneity are also considered. Furthermore, by introducing imaginary nodes to map the heterogeneous ring network to equivalent the homogeneous (EHM) ring network with identical delay, the relationship between such zero-lag correlation properties of intensity chaos and the greatest common divisor (GCD) of the EHM ring network loop length is revealed. It is shown that, when the coupling rate is sufficiently large, two types of zero-lag synchrony patterns, zero-lag global synchrony and zero-lag cluster synchrony, can be found in the same ring network, depending on the GCD of the delay loops composing the network. That is to say, by carefully adjusting the coupling delays ratio one can deliberately switch between two different zero-lag synchrony patterns in the same laser ring network, which may be interesting for the field of chaos synchronization. High-quality synchronization can be obtained in wide range of coupling rate, and is robust to small frequency detuning and slight mismatched internal laser parameters. The dependence of zero-lag synchronization of intensity chaos may provide useful guidelines for designing multi-user chaos optical communication among ring networks.