The optical amplifier (1) comprises optical components (2-13), connection light guide sections (14) between the optical components, and electronic and electrical power supply and control components (41,42). It is characterized in that it comprises:an optical unit (15) comprising the optical components (2-13) and the connection light guide sections (14).an electronic unit (16) comprising the electronic and electrical components (41,42) and being separate from the optical unit (15), andmeans (43,44) of electrical interconnection between the optical unit (15) and the electronic unit (16).The clear separation of the electronic components (41,42) from the optical components (2-13) affords size reductions and rationalization of the amplifier (1) implementation procedure.