Why some optical module is dual cores while some is single core? What are the differences between them?

For two-fiber bidirectional optical module, there are two optical fibers, one receives and the other sends, the wavelengths can be the same.

For BiDi, there is only one optical fiber and send different wavelengths, if one side sends by 1310nm and receives by 1270nm, the other side must send by 1270nm and receives by 1310nm.

The single core optical module may transport in one way, which is sending at one side and receiving at the other side.

Tags: BiDi Optical modules