This part of IEC 61290 applies to optical fibre amplifiers (OFAs) using active fibres, containing rare-earth dopants, presently commercially available. The object of this part of IEC 61290 is to establish uniform requirements for accurate and reliable measurements, by means of the electrical spectrum analyser test method, of the following OFA parameters, as defined in IEC 61291-1: a) input reflectance; b) output reflectance. NOTE 1 All numerical values followed by (‡) are currently under study. NOTE 2 The measurement uncertainty should be better than ±1 dB.