Development of a multichannel fiber-to-fiber optical connector for the DO upgrade tracker

A tracking detector using scintillating fibers is being developed for the DO collaboration at Fermilab. The scintillating fibers will be coupled to clear fibers that will transport light to the photodetectors. We have developed connectors which couple the two types of fibers. The first 128-channel prototypes were machined using Delrin plastic to have v-shaped grooves. Fibers were glued into the grooves and their ends were finished with diamond fly-cut tools. Mating connectors were optically coupled by optical grease. Using a green light-emitting diode and a silicon photodiode, we measured average light transmission between 97% and 99%. Later versions of the v-groove connectors were made of acrylonitrile-butadienestyrene plastic by injection molding.