This Standard applies to fibre optic wavelength switches. The term ""fibre optic wavelength switch"" can be used to describe a wide range of devices, assemblies and systems both active and passive. Therefore, it is necessary to elaborate on the scope and object of this standard. This specification is intended to cover those devices and assemblies which have the following attributes. While the switch actuation means is by necessity active, the optical paths through the switch are passive. Thus, neither optical amplification nor opto-electronic conversion is encompassed. The switch function is restricted to the routing of light rather than intentional power d