IEC 61300-3-7:2009 describes the various methods available to measure the wavelength dependence of attenuation and return loss, of single-mode passive optical components (POC) used in fibre-optic (FO) telecommunications. This second edition cancels and replaces the first edition published in 2000. Changes from the previous edition of this standard are to reflect changes made to IEC 61300-1 and covers unidirectional and bi-directional methods of measurement.