AN OPTICAL PON NETWORK USING PASSIVE DPSK DEMODULATION

摘要

An optical PON network comprises a central office which generates N DPSK modulated optical signals, where N is an integer greater than 1, an optical coupling which connects the N signals to at least one optical fibre, a passi ve distribution node located remotely from the central office which has at l east one input port that is coupled to the fibre and a plurality of output p orts, the node being arranged to transmit a first wavelength of the N signal s to at least one of its output ports, and at least one optical network unit connected through a respective optical fibre to the first output port of th e passive distribution node. The passive distribution node comprises an arra yed waveguide grating which provides a passive optical connection between it s input port and the first output port and which for that connection functio ns as a bandpass filter having a profile and bandwidth selected such that th e DPSK optical signal passed to the input node is converted to an intensity modulated signal at the output port.