Fiber Optic Ceramic Ferrule Size Standards

Ceramic fiber optic ferrules typically have precise inner diameters from 80 µm to 1100 µm, outer diameters of 1.25 mm or 2.5 mm, and lengths ranging from 2.5 mm to 22.5 mm, with submicron tolerances for high-precision alignment.

Standard Dimensions

Inner Diameter (Bore Size): Ceramic ferrules are designed to align optical fibers with high precision. Bore sizes range from 80 µm to 1100 µm, depending on singlemode or multimode fiber requirements and connector type (LC, SC, FC, ST, MU) . The inner diameter is polished to a tolerance of ±0.001 mm in concentricity and ±0.0005 mm in eccentricity for singlemode ferrules . Outer Diameter (OD): Common standard outer diameters are 1.25 mm for LC ferrules and 2.5 mm for FC, SC, and ST ferrules . The OD is ground and polished to a controlled submicron level to ensure proper mating with connector housings . Length: Ferrule lengths vary by type and application. Typical lengths include 4.9 mm to 8.1 mm for bare ceramic ferrules, with flanged versions extending up to 16 mm . Custom ferrules can range from 2.5 mm to 22.5 mm .

Material and Manufacturing

Ceramic ferrules are usually made from zirconia or alumina, providing excellent mechanical stability, non-magnetic properties, and high wear resistance . Precision is achieved through extrusion molding and precision machining, ensuring excellent coaxiality and concentricity between the bore and outer diameter . The end face can be polished to customer specifications, including PC or APC polishing .

Tolerances and Alignment

High-precision ferrules maintain submicron tolerances to ensure accurate fiber alignment. The inner diameter is slightly larger than the fiber OD to allow insertion, while maintaining tight concentricity for minimal optical loss . Concentricity and eccentricity tolerances are critical for singlemode fibers used in optical communication.

Summary

• Bore (ID): 80 µm – 1100 µm
• Outer Diameter (OD): 1.25 mm (LC) or 2.5 mm (FC/SC/ST)
• Length: 2.5 mm – 22.5 mm (bare or flanged)
• Material: Zirconia or alumina ceramic
• Tolerances: ±0.001 mm concentricity, ±0.0005 mm eccentricity for singlemode ferrules
• Applications: Singlemode, multimode, PM fibers, and specialized optical connectors These specifications ensure precise fiber alignment, low insertion loss, and compatibility with standard optical connectors.