IEC 62077:2010(E) applies to fibre optic circulators, which are: - non-reciprocal optical devices; - passive components; - have three or more ports for directionally transmitting optical power. This standard establishes circulator requirements and quality assessment procedures. The changes with respect to the previous edition are listed as: - having substantially increased the number of terms; - having added an informative annex for examle of filtering technologies; - having deleted quality assessment procedures.