2. Fiber-to-fiber connectivity

2.1 Classification according to the alignment principle

The purpose of optical connectivity is to bring the cores of the upstream and downstream fibers into contact with each other, so there's no need for contact or friction as with electrical connectivity. What's more, it's necessary to prepare the end of each fiber (polishing or cleaving). Fiber-to-fiber connectivity is symmetrical.

The connection consists of three elements: a plug at each end of the fibers to be connected, and a connector between these two plugs. The plug/connector/socket structure is symmetrical, and there is no male/female structure, as in electrical connectors.