Patent ID: 8260141

Claim:
A system for enabling reconfiguration of a Wavelength Division Multiplexed (WDM) optical communications network comprising active and inactive wavelength channels, the system comprising: a broadband light source for generating a broadband continuous wave light having a bandwidth corresponding to a channel band of the network; a wavelength selective switch comprising: a first switch port connected to receive one or more active wavelength channels; a second switch port connected to receive the broadband continuous wave light from the broadband light source, the wavelength selective switch being configured to comb the broadband continuous wave light into a plurality of narrowband lights respectively corresponding with wavelength channels of the network; and a common-OUT port for outputting a WDM signal for transmission through a downstream fibre span of the network; wherein the wavelength selective switch is controlled to switch the active wavelength channels to the common-OUT port of the wavelength selective switch and to selectively switch narrowband lights corresponding to inactive wavelength channels to the common-OUT port, such that the WDM signal output from the common-OUT port has a spectral loading of 100%, independent of the number of active wavelength channels.