Development of a Novel Vibration Polishing Method for Fiber Protrusion in Multi-fiber Connectors

2.1 Fiber Endface Conditions Required for PC Connection Figure 1 shows the structure of an 8-fiber MPO connector. To decrease reflection, fiber endfaces in this kind of connector are polished at a gradient of 8° to the fiber cross section. The connector endfaces are held together by the engagement of the guide pins in guide-pin holes. To achieve PC connection in such a connector, it is necessary that the process of polishing achieve the following three main elements: 1. sufficient fiber protrusion, 2. flat endfaces, and 3. angular precision between the fiber endface and the connection endface. The novel polishing method enables us to achieve PC connection since all three of these conditions are achieved by polishing connector and fiber ends separately, guaranteeing the flatness of fiber endfaces.