This international standard applies to all commercially available optical amplifiers (OAs) and optically amplified subsystems. It applies to OAs using optically pumped fibres (OFAs based on either rare-earth doped fibres or on the Raman effect), semiconductor optical amplifiers (SOAs) and waveguides (POWA).The object of this international standard is to establish uniform requirements for accurate and reliable measurements, by means of the interpolated source subtraction method using an optical spectrum analyzer. The following OA parameters, as defined in Clause 3 of IEC 61291-1, are determined:• Channel gain, and• Channel signal-spontaneous noise figure.Thi