Development of fiber-to-fiber connectors for scintillating tile/fiber calorimeters

We have developed fiber-to-fiber connectors for plastic fibers of 0.83, 0.90, and 1.00 mm in diameter. Such a connector is essential for detectors that use a large number of optical fibers, scintillating or clear. Typical applicators are unscintillating tile/fiber calorimetry and scintillating fiber tracking. We describe the design and performance of two types of small 10-fiber connectors which were developed for the CDF endplug tile/fiber calorimeter. The connectors showed a light transmission of 85–90% with a uniformity of 2.5–3.1%, and a reproducibility of 1%. Use of optical matching material at the joints could further improve the transmission and uniformity but showed instability after heat cycles.