IEC 62077:2010 applies to circulators used in the field of fibre optics bearing all of the following features:
- they are non-reciprocal optical devices, in which each port is either an optical fibre or fibre optic connector;
- they are passive devices in accordance with the categorization and definition provided in IEC 62538; and
- they have three or more ports for directionally transmitting optical power.
The changes with respect to the previous edition are:
- having substantially increased the number of terms;
- having added an informative annex for example of filtering technologies;
- having deleted quality assessment procedures.