This part of IEC 61290 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), semiconductors (SOAs), and waveguides (POWAs). It is specifically directed to single-channel amplifiers. Test methods for multichannel amplifiers are defined in the IEC 61290-10 series. This standard establishes uniform requirements for accurate and reliable measurements of the following OA parameters, as defined in Clause 3 of IEC 61291-1: a) nominal output signal power; b) gain; c) reverse gain; d) maximum gain; e) maximum gain wavelength; f) maximum gain variation with temperature; g) gain wavelength band; h) gain wavelength variation; i) gain stability; j) polarization-dependent gain; k) gain ripple (SOA only); l) large-signal output stability; m) saturation output power; n) maximum output signal power; o) maximum total output power. NOTE 1 The applicability of the test methods described in the present standard to distributed Raman amplifiers is still under study. NOTE 2 All numerical values followed by (! ).are suggested values for which the measurement is assured. Other values are acceptable if verified.