Bubbling in delay-coupled lasers

We numerically and analytically study the isochronous (zero-lag) chaos synchronization of two Lang-Kobayashi type lasers which are delay-coupled via a passive relay (semitransparentmirror) [1,2] or an active relay (third laser) [3,4]. We show that both relay setups exhibit bubbling [5,6], i. e., noise-induced desynchronization, or on-off intermittency depending on the coupling parameters.