Monolithic photonic integrated circuit and opto-electronic system comprising the same

A monolithic indium phosphide, InP,-based photonic integrated circuit comprising:

• a first photonic assembly that comprises:
• a first optical splitter-combiner unit having a first end part that is provided with at least a
• first optical interface and a second end part that is provided with at least a second optical interface and a third optical interface;
• a first optical waveguide that is arranged in optical communication with the first optical interface of the first optical splitter-combiner unit;
• a first main photonic circuit that is arranged in optical communication with the second optical interface of the first optical splitter-combiner unit;
• and
• a first auxiliary photonic circuit that is arranged in optical communication with the third optical interface of the first optical splitter-combiner unit, the first auxiliary photonic circuit comprising:
• a first laser unit;
• and
• a first semiconductor optical amplifier, SOA, having a first end facet that is arranged in optical communication with the third optical interface of the first optical splitter-combiner unit, and a second end facet that is arranged in optical communication with the first laser unit, the first SOA being configurable to be in:
• a first operational state in which optical communication between the first laser unit and the first optical splitter-combiner unit is allowed;
• or
• a second operational state in which optical communication between the first laser unit and the first optical splitter-combiner unit is prevented;
• and
• a second photonic assembly that comprises:
• a second optical splitter-combiner unit having a third end part that is provided with at least
• a fourth optical interface and a fourth end part that is provided with at least a fifth optical interface and a sixth optical interface;
• a fifth optical waveguide that is arranged in optical communication with the fourth optical interface of the second optical splitter-combiner unit;
• a second main photonic circuit that is arranged in optical communication with the fifth optical interface of the second optical splitter-combiner unit;
• and
• a second auxiliary photonic circuit that is arranged in optical communication with the sixth optical interface of the second optical splitter-combiner unit, the second auxiliary photonic circuit comprising:
• a second laser unit;
• and
• a third SOA having a fifth end facet that is arranged in optical communication with the sixth optical interface of the second optical splitter-combiner unit, and a sixth end facet that is arranged in optical communication with the second laser unit, the third SOA being configurable to be in:
• a first operational state in which optical communication between the second laser unit and the second optical splitter-combiner unit is allowed;
• or
• a second operational state in which optical communication between the second laser unit and the second optical splitter-combiner unit is prevented;
• wherein the first photonic assembly and the second photonic assembly are configured to allow optical radiation that is guided by the first optical waveguide of the first photonic assembly and optical radiation that is guided by the fifth optical waveguide of the second photonic assembly to have different optical polarization states.