How to set the origin point of a ceramic ferrule PC

The origin point of a ceramic ferrule PC is set by aligning the fiber apex to the ferrule's spherical or planar reference surface, ensuring minimal apex offset and proper physical contact.Understanding the Ferrule and PC ConnectorA ceramic ferrule is a precision component that holds the optical fiber in a fixed, central position, typically made of zirconia for its stability, hardness, and thermal compatibility with glass fibers . In a PC (Physical Contact) connector, the fiber endface is polished to a slightly convex shape to ensure direct contact with the mating fiber, reducing back reflection and insertion loss .Defining the Origin PointThe origin point refers to the reference apex of the ferrule's endface, which is used to measure fiber protrusion, apex offset, and planar height. Properly setting this point ensures that the fiber core aligns with the connector axis and the mating fiber:Apex Offset: The distance between the highest point of the ferrule sphere and the fiber core center. Ideally, this should be minimized to maintain optimal contact .Planar Height: The difference in height between the fiber tip and the theoretical plane of the ferrule surface. This is used to assess fiber protrusion and undercut .Procedure to Set the Origin PointMount the Ferrule in a Jig: Use an Individual Pressure Control (IPC) fixture or spring-loaded adapter to hold the ferrule securely while allowing slight movement for uniform polishing .Initial Polishing: Begin with a coarse lapping film (e.g., silicon carbide) to remove epoxy and achieve a consistent fiber protrusion. Apply minimal hand pressure and rotate gently to avoid fiber breakage .Check Fiber Height: Measure the fiber tip relative to the ferrule surface using a microscope or interferometer. Adjust the ferrule position in the jig to align the fiber apex with the reference plane or spherical surface.Fine Polishing: Progress through finer lapping films or diamond films to achieve the desired convex endface. Ensure the apex is centered and the fiber protrusion is uniform across all ferrules .Verify Apex Offset: Confirm that the apex offset is within the acceptable range (typically