DIN EN 60793-1-41:2011-06

This part of IEC 60793 describes three methods for determining and measuring the modal bandwidth of multimode optical fibres (see IEC 60793-2-10, IEC 60793-2-30 and IEC 60793-2-40). The baseband frequency response is directly measured in the frequency domain by determining the fibre response to a sinusoidaly modulated light source. The baseband response can also be measured by observing the broadening of a narrow pulse of light. The calculated response is determined using differential mode delay (DMD) data. The three methods are: - Method A - Time domain (pulse distortion) measurement - Method B - Frequency-domain measurement - Method C - Overfilled launch modal bandwidth calculated from differential mode delay (OMBc). Methods A and B can be carried out using one of the following launch types: overfilled launch (OFL) condition or restricted mode launch (RML) condition. Method C is only defined for A1a.2 (and A1a.3, under preparation) multimode fibres and uses a weighted accumulation of DMD excitation responses with weighting of the associated overfilled launch condition. The relevant test procedures and launch conditions should be selected in accordance with the type of fibre. The responsible Committee is Subcommittee UK 412.7 "LWL-Verbindungstechnik und passive optische Komponenten" ("Fibre optic interconnecting devices and passive optical components") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.