Semiconductor optical amplifier device and optical matrix switch

A semiconductor optical amplifier device comprising:

• a plurality of active units, each active unit comprising an active stripe structure of an optical amplifying medium, a current circuit for injecting current into the active stripe structure and an individual output reflector structure at an output end of its active stripe structure;
• wherein each active stripe structure extends from an input end to the output end;
• an optical splitter device for splitting incoming signal light and for distributing corresponding parts of the incoming signal light into the different input ends of the active stripe structures, wherein the optical splitter device is configured to supply each active stripe structure with the same signal information;
• and
• a common input reflector structure spanning across the plurality of input ends of the active stripe structures.