This part of IEC 61290-1 applies to all commercially available optical amplifiers (OA) and optically amplified subsystems. It applies to OA using optically pumped fibres (OFA based on either rare-earth doped fibres or on the Raman effect), semiconductors (SOA), and waveguides (POWA). NOTE The applicability of the test methods described in the present standard to distributed Raman amplifiers is for further study. The object of this part of IEC 61290-1 is to establish uniform requirements for accurate and reliable measurements, by means of the optical power meter test method, of the following OA parameters, as defined in IEC 61291-1: a) nominal output signal power; b) gain; c) polarization-dependent gain; d) maximum output signal power; e) maximum total output power. All numerical values followed by (‡) are suggested values for which the measurement is assured. Other values may be acceptable but should be verified. This part of IEC 61290-1 applies to single-channel amplifiers. For multichannel amplifiers, the IEC 61290-10 series applies.