On the technical room, optical fiber cable is terminated by special ODF-block. Further consumer equipment should be connected to it by special optical patch cords, consisting of a piece of flexible fiber and pairs of optic connectors (sometimes of different types).

Nowadays many types of plug connectors for optical communication are used. Structurally, this is special terminated fiber with qualitative short-focus lens, equipped with the shell and releasable locking device which fulfills the necessary requirements for reliability and ease of disconnection. In the transport position lens is closed by special plastic cap which must be removed directly before the connection.

Fig.2. Type and appearance of optical connectors (taken from the internet)

All of them are specific for each type of equipment and application. In addition, they have their standardized level of losses, because some percentage of the radiation energy is always lost at interfaces (light goes path like: quartz-lens-air-lens-quartz).