Switching status and performance monitoring technology for wavelength selective switch and optical networks

Abstract

A universal in-service monitoring scheme to monitor performances of optical networks, including elements that make up the optical network, is proposed. The elements may be a wavelength selective switch or an optical cross connect. In this scheme, a small tunable probe signal is injected into the optical network via an input of the network. An output signal is received at the output and processed to determine if the probe signal is contained within the output signal. The scheme is such that probe signal injection and detection devices need not be physically co-located. Thus, the scheme is useful to test even optical network that spans thousands of miles. The probe signal is non-interfering with the network traffic so the network can be providing service while its performance is monitored. As examples of the probe signal detection mechanisms include lock-in amplification and coherent detection.