Abstract: The invention relates to an optical coupling unit for an arrangement for sending optical signals, including a base unit, a light path formed between a light input and a light output of the base unit and configured to transmit light received via the light input to the light output, an outer light path section included in the light path, which section extends outside the base unit and into which the light transmitted along the light path emerges from the base unit via a light exit and from which the light after passing through the outer light path section enters again into the base unit via a light entry, and a light decoupling element, which is formed in the light path by means of at least one beamsplitting surface coating and configured to decouple a portion of the light transmitted along the light path. Furthermore the invention relates to an arrangement for sending optical signals and to an optical transceiver.