conical connector
The lens connector is a special FO connector with built-in lens coupling.
Lens connectors are designed in such a way that the light beam to be transmitted is broadened when exiting one optical fiber and bundled again when entering the other fiber. Between the two microlenses, the light beams are guided in parallel through glass plates.
This connection technique has the advantage of being relatively insensitive to contamination. An even stronger spreading and bundling has the EBO connector, whose lenses are spherical.