Patent ID: 6650809
Filing Date: 2003-11-18
Classification: G02B,H04J

Abstract:
An optical network having a predetermined application wavelength window comprising:a plurality of optical band add-drop nodes each comprising a demultiplexing device supporting multiple wavelength bands within the application wavelength window including: an input port for receiving a multiplexed optical signal including optical signals within each of a plurality of wavelength channels having a predetermined channel spacing within an add-drop wavelength band corresponding to any one of a plurality of nonoverlapping wavelength bands within the application wavelength window; at least three output ports; and a wavelength dispersive element for separating the multiplexed optical signal received at the input port in dependence upon wavelength to provide a channelised signal to each of the at least three output ports, a multiplexing device supporting multiple wavelength bands within the application wavelength window including: an output port for receiving a multiplexed optical signal including optical signals within each of a plurality of wavelength channels having a predetermined channel spacing within a same add-drop wavelength band corresponding to any one of a plurality of nonoverlapping wavelength bands within the application wavelength window; at least three input ports; and a wavelength dispersive element for combining the channelised optical signals received at the input ports in dependence upon wavelength to provide a multiplexed signal to the output port, a first optical band pass filter for separating optical channels within said add-drop wavelength band from those of other wavelength bands and for providing optical signals within the optical wavelength channels within the add-drop wavelength band to the input port of the demultiplexing device; and, a second optical band pass filter for receiving optical signals within other wavelength bands from the first optical band pass filter and for combining the same with the optical signals within optical wavelength channels within the add-drop wavelength band received from the output port of the multiplexing device, wherein the add-drop wavelength bands for a set of different nodes are different and wherein the multiplexing and demultiplexing devices for a same set of different nodes are identical, wherein at different nodes a signal within a different wavelength channel is directed toward a same output port of the identical devices.