Method and system for avoiding amplified spontaneous emission loops in an optical network

Abstract

Optical communication networks often incorporate fiber rings or fiber mesh topologies for interconnecting its nodes. Both of these topologies can contain closed optical loops at one or more wavelengths within the optical spectrum. In amplified optical systems, the inherent loss of these optical loops is counteracted by the amplifier gain. Thus, the optical loop may have a net loss that is too low to prevent excessive noise buildup resulting in a lasing fiber loop. The noise that builds up within such amplified systems is dominated by the Amplified Spontaneous Emission (ASE) noise resulting in ASE loops. Such loops can have a serious impact on all wavelengths carried by the fiber and lead to a partial or complete loss of end to end communication due to a severe degradation in signal to noise ratio. This invention provides an effective method and system for avoiding ASE loops in optical communication networks. The method deploys optical seams as well as a unique signature for a wavelength instance for achieving an effective solution that is resilient to errors and failures that may occur on the system both during service creation and normal operation.