Optical network unit, optical access network and a method for exchanging information

An Optical Network Unit (ONU), comprising:

• an port that is arranged to receive downstream signals that comprise a pilot signal and downstream information signals;
• wherein the downstream information signals embed first polarization modulated information and second polarization modulated information;
• wherein the pilot signal is received at a pilot frequency slot and the downstream information signals are received at a downstream information frequency slot that differs from the pilot frequency slot;
• a splitting module that is arranged to split the downstream signals to first, second, third and fourth sets of signals;
• wherein the splitting module comprises a polarization based splitter that is arranged to perform a polarization based splitting to provide first and second intermediate sets of signals;
• wherein the first and second sets of signals originate from the first intermediate set of signals and the third and fourth sets of signals originate from the second intermediate set of signals;
• a polarization changing circuit that is arranged to receive the second and fourth sets of signals and to generate a fifth set of signals;
• wherein a polarization direction of the fifth set of signals differs from a polarization direction of the first and second intermediate sets of signals;
• a detection module that is arranged to generate first, second and third sets of detection signals, in response to the first, third and fifth sets of signals;
• and
• a reconstruction module that is arranged to reconstruct the first polarization modulated information and the second polarization modulated information in response to the first, second and third sets of detection signals.