Connecting piece and optical fiber connector

An optical fiber connector, comprising:

• a flat drop cable;
• a connector sub-assembly comprising a ceramic ferrule, wherein one end of the connector sub-assembly is configured to be fastened to the flat drop cable;
• a coupling shaft, wherein the coupling shaft is step-shaped and comprises:
• a flange;
• and
• a plastic body, wherein a first end of the plastic body is provided with an internal thread configured to connect to an external thread of the connector sub-assembly, wherein the flange is located at a second end of the plastic body opposite the first end and is provided with at least one hook groove, wherein the at least one hook groove is an opening cut in an outside surface of the flange, wherein the opening has an arc-shaped edge, and wherein a strength member inside the flat drop cable is separated from the flat drop cable on the end of the flat drop cable and bent to hook the at least one hook groove;
• an elastic component configured to sleeve the coupling shaft;
• an inner sleeving element configured to accommodate the connector sub-assembly, wherein one end of the inner sleeving element is higher than an end surface of the ceramic ferrule, and wherein the inner sleeving element is provided with an open slot such that a cross section of the inner sleeving element is C-shaped;
• and
• an outer sleeving element, wherein the outer sleeving element is configured to sleeve the inner sleeving element, wherein the outer sleeving element is capable of sliding forwards and backwards relative to the inner sleeving element, wherein one end of the outer sleeving element forms an inner shaft shoulder inwards, which is configured to abut on the other end of the elastic component, and wherein an inner wall of the outer sleeving element is provided with at least one protruding projection configured to buckle with an adapter when the optical fiber connector is plugged into the adapter.