IEC/TR 61292-9@ which is a technical report@ focuses on SOAs@ especially the specific features and measurement of gain and PDG. In this report@ only the amplifying application of SOAs is described. Other applications@ such as modulation@ switching and non-linear functions@ are not covered. Potential applications of SOAs@ however@ such as reflective SOAs (RSOAs) for the seeded wavelength division multiplexing passive optical network (WDM-PON)@ are briefly reviewed in Annex A.