IEC 62074-1:2009(E) applies to fibre optic wavelength division multiplexing (WDM) devices. These have all of the following general features:
- they are passive, in that they contain no optoelectronic or other transducing elements; but
- they may use temperature control only the purpose to stabilize the characteristics of devices;
- they exclude any optical switching function;
- they have three or more ports for the entry and/or exit of optical power, and share optical power among these ports in a predetermined fashion depending on the wavelength;
- the are optical fibres or optical fibre connectors.