Applies to commercially available optical amplifiers (OAs) such as optical fibre amplifiers (OFAs), semiconductor optical amplifiers (SOAs) and planar wageguide apmlifiers (PWOAs) as classified in IEC 61292-3.The object is to establish uniform requirements for accurate and reliable measurements, by means of optical spectrum analyzer (OSA) test method, of the following OA parameters, as defined in IEC 61291-1: a) signal-spontaneous noise figure, b) forward amplified spontaneous emission (ASE) power level. The methods outlined in this part of IEC 61290 apply to single-channel stimulus only.