Patent ID: 8478125
Filing Date: 2013-07-02
Classification: H04B,H04J,H04Q

Abstract:
1. An optical network comprising: a central office which is arranged to generate N differential phase shift key modulated optical signals, where N is an integer greater than 1, optical coupling means arranged to connect the N signals to at least one optical waveguide, a passive distribution node located remotely from the central office which has at least one input port that is coupled to the waveguide and a plurality of output ports, the node being arranged to transmit a first wavelength of the N signals to at least one of its output ports, and at least one optical network unit connected through a respective optical wave guide to the first output port of the passive distribution node, wherein the passive distribution node comprises an arrayed waveguide grating arranged to provide a passive optical connection between its input port and the first output port and which for that connection functions as a bandpass filter having a profile and bandwidth selected such that the differential phase shift key modulated optical signal passed to the input port is converted to an intensity modulated signal at the output port.