What is the Fiber Optic Ferrules?

1.what is the fiber optic ferrule?

Fiber optic ferrules are mechanical fixtures, generally rigid tubes, which are used to confine the stripped end of a fiber or a fiber bundle. They align and polish optical fibers to prevent the scattering and dampening of the light signal. Most fiber optic ferrules are made of metals such as stainless steel, ceramics such as alumina or zirconia, or plastic materials. Fiber optic ferrules made of borosilicate glass and glass are also available. Most fiber optic ferrules are manufactured with direct-draw or redraw processes and cut to length with diamond saw blades. To prevent problems such as splice loss and end gaps, they are bored through the center at a diameter which is slightly larger than that of the fiber cladding. Lead-ins are then blown, acid-etched, or drilled countersunk.

Ferrule is the most important component of Fiber Connectors and Fiber Patch cord

The outer diameter (OD) Ceramic (Zirconia) Ferrule size for ST, FC and SC Fiber Connectors is φ2.5mm, The OD Ceramic(Zirconia) Ferrule size for the MU and LC Fiber Connector Versions is φ1.25 mm. The OD Ceramic (Zirconia) Ferrules size is precise with a tolerance level of ±0.0005 mm. The inner diameter (ID) Ceramic Ferrules size has a precision of 0.001mm in concentricity and 0.0005mm in eccentricity for the singlemode ferrules used for optical communication components.

The OD Ceramic Ferrules size is precise with a tolerance level of ±0.001 mm. The inner diameter (ID) Ceramic Ferrules size has a precision of 0.003mm in concentricity and 0.004mm in eccentricity for the multimode ferrules used for LAN and/or SAN Applications.

Type	OD	concentricity	ID	Length
SM	2.499/1.249mm	<=1.0um	125-126/126-127um	10.4-10.5/6.4-6.5mm
MM	2.499/1.249mm	<=3.8um	126-130um	10.4-10.5/6.4-6.5mm

2.how to select good ferrule?

Selecting fiber optic ferrules requires a careful analysis of product specifications and features. Fiber optic components for both single-mode and multi-mode fibers are commonly available. For both types of optical fibers, ferrule specifications such as inner diameter (ID), outer diameter (OD), length, concentricity, radius, and bore style are important to consider. Choices for bore style include single bore, double bore, and racetrack bore. Fiber optic ferrules with square and rectangular bores are also available. In terms of features, some fiber optic ferrules have a multi-step ID or a multi-step OD. Others have countersinks, anti-rotation notches, flats, slots, grooves, epoxy vent holes, and any-angle chamfers.

3.The production process of Ceramic Ferrules

A.semifinished production

Dioxide-Injection molding-Degreasing-sintering-cooling-Storage

B.Production processing

semifinished product-first polish of Outer diameter-Length polishing-Inner Diameter polishing-Concentricity polishing -Length second polishing-Outer second diameter polishing-angle polishing-spherical surface polishing-Outer diameter final polishing

4.Inspection

A.Inspection processing

Appearance–Length–Dimensions-Concentricity

B.Inspection Detail

1. Appearance
1.1. Neatly and firmly packed with pass stamp and testing reports;
1.2. Ceramic parts neat and clean with consistent color; No spots, cracks and burr edges;
Consistent angle; End face must be protruding sphere. APC wimble diameter is
1.0mm(can be 1.4mm upon customer request), APC stepped type can be measured with
dig-caliber. Taper type can’t be measured. Check the test report from the supplier.
1.3. Flange must be shining without burr edges. Metal part must be stainless steel or bronze.
1.4. The whole body has no bending or distortion

2. Dimensions
SC/FC/SC Outer Diameter: Φ2.499±0.001
Flange slot width: For APC 1.38-1.43 mm，and for PC 1.4-1.6 mm. The four
slots must be the same and the tolerance is no more than 0.1mm.
Flange length: 8.05±0.1 or 16.5±0.1/19.5±0.1
LC Length: 6.5±0.05mm OD：Φ1.24
Inner Diameter of ferrule: SM 1253(125.3-126.3)/1255(125.5-126.5)1260(126.0-127.0um)
MM 1260(126.0-129.0)/1270(127.0-130.0um)
No jam in the bore; 125um bare fiber can be put through easily, so do the same size stainless pin.

3. Performances(together with qualified connector and simplex cable):
PC: IL ≤0.3dB RL≥50 dB; APC：IL≤0.3dB ，RL ≥60 dB
Sampling for ferrule suppliers must be testes once every month and the results must be well-kept.

4. Inspection for Acceptance
For every batch, sampling inspection must be done under Orientation for Inspection. Detail
requirements are as follows:
4.1. Appearance: Type II: AQL=2.5
4.2. Dimensions: Type II: AQL=0.65
4.3. Performance: Type II: AQL=0.65
When all the above criterions are met, can they be accepted as Qualified.