This International Standard applies to all commercially available optical amplifiers (OAs), including OAs using optically pumped fibres (OFAs based on either rare-earth doped fibres or on the Raman effect), semiconductor optical amplifiers (SOAs) and planar waveguide optical amplifiers (PWOAs). The object of this International Standard is to establish uniform requirement for accurate and reliable measurements, by means of the electrical spectrum analyzer (ESA) method, of the noise figure, as defined in International Standard IEC 61291-1. The present test method is based on direct electrical noise measurement and it is directly related to its definition incl