IEC 61290-1:2014 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). The object of this standard is to establish uniform requirements for accurate and reliable measurements of the following OA parameters, as defined in Clause 3 of IEC 61291-1:2012:- nominal output signal power;- gain;- reverse gain;- maximum gain;- maximum gain wavelength;- maximum gain variation with temperature;- gain wavelength band;- gain wavelength variation;- gain stability;- polarization-dependent gain;- large-signal output stability;- saturation output power;- maximum output signal power;- maximum total output power. The object of this standard is specifically directed to single-channel amplifiers. For multichannel amplifiers, one should refer to the IEC 61290-10 series.Keywords: optical amplifiers (OAs), optically pumped fibres (OFAs), semiconductors (SOAs), and waveguides (POWAs)