opposed optical devices as shown in fig1 the u shaped optical fiber system 39 may be inserted between the pair of opposed optical devices so that it extends between the corresponding pair of adjacent printed circuit boards e g optical fiber systems 22 and 26 or extend outside of the region between the printed circuit boards e g optical fiber system 24 referring to fig3 a 3 f in another optical fiber system 50 a positioner 52 is configured to releasably receive a multi fiber fiber optic ribbon cable 56 fig3 a and bias it into engagement with a pair of opposed optical devices 58 and 60 fig3 d the fibers of ribbon cable 56 extend beyond the surrounding support matrix so that they may be coupled to optical devices 58 60 the optical fibers may extend beyond the support matrix by a distance of about 0 5 cm to about 3 cm positioner 52 includes a pair of cantilevered support arms 62 64 respectively coupled to a plurality of distal support fingers 66 68 support fingers 66 68 are interleaved when positioner 52 is in the engaged configuration fig3 e and 3f and they are almost end to end when positioner 52 is in the disengaged configuration fig3 b and.