Key factors in the quality of optical connectors and patch cables include the special geometric characteristics of the end surfaces in a ferrule. Some of these characteristics, such as, for example, the polishing radius, apex offset, or fiber protrusion, can be measured with an interferometer; however, the concentricity cannot be measured. (Something is concentric when it is arranged symmetrically around a common center.)
For example, a conventional interferometer cannot be used to determine how concentric the fiber core is in relationship to the edge of the ferrule. The concentricity of a fiber core can be influenced by different tolerances: fiber core to fiber cladding, ferrule edge to ferrule bore, and the fiber diameter does not match the diameter of the bore. The result of this concentricity leads to a loss in optical power and a greater attenuation.
The KONCENTRIK-V2 is a modular measuring system with which one can measure the concentricity of either optical fibers or optical ferrules. For different measurements the mechanical measurement adapter is simply exchanged and the same basic device used.
Ferrule module: The ferrule is measured prior to gluing the fiber.
With the ferrule module, the KONCENTRIK-V2 measures the concentricity of the ferrule bore in relationship to the outer ferrule cladding at a tolerance of less than 0.15 µm. This device determines the angle position of the bore – in relationship to the connector key – which is important, for example, for tuning optical connectors. Both the diameter of the bore and the erroneous circularities of the outer ferrule cladding and ferrule bore are also a part of the measurement parameters.
Connector module: The ferrule is measured after gluing the fiber.
With this module, the KONCENTRIK-V2 measures the concentricity of the fiber core in relationship to the ferrule edge of an optical connector at an accuracy of 0.15 µm. In addition, the position of the core in relationship to the connector key can also be determined for tuning optical connectors.
