A folded cavity semiconductor optical amplifier is provided that includes a first mirror disposed on a substrate of semiconductor material and an active region formed thereon consisting of an optical cavity with a gain medium. A preferably metallic signal conductor can be connected to the signal-emitting subject, preferably in the form of a signal-conducting layer, and is arranged between an upper top layer and an adhesive layer which can be brought into contact with the signal-emitting subject. The base includes at least one air inlet for delivering air to the air chamber and the rotor includes at least one air outlet for air flow out of the chamber. The register file has a first section of n registers and a second section of m registers.