Reference connectors for measurement purposes
Optical reference connectors are manufactured with restricted tolerances and are used for attenuation measurement purposes; these shall be considered as part of the measurement set-up since they strongly contribute to its measurement uncertainty.
In order to limit the variability of attenuation measurement using reference connectors, Diamond uses selected single mode fiber with restricted tolerances on (MFD) as specified within the IEC 61755-2-4 / -2-5 standard. Using only this type of fiber and the tolerance parameters published in the standards mentioned below, it is possible to reach measurement values that are repeatable within ± 0.1 dB when randomly varying the reference connector. The main parameters influencing the performance of the reference connectors are fiber core location, fiber core axis angle and mode field diameter (MFD) variability. Diamond manufactures high performance reference connectors using the standardized composite ferrule, as well as "Active Core Alignment" (ACA) technology, which allows for the minimization of the fiber core eccentricity and the control of the angular misalignment.