Abstract: An optical busbar, for optically interconnecting electronic and/or photonic equipment, comprises a rod of light-transmissive material, for example polycarbonate, having a longitudinal planar surface. Preferably the rod is of polygonal cross-sectional shape. Distributed along its length, opposite the planar surface, the rod has a plurality of inclined reflector surfaces for diverting light travelling along the rod so that it emerges laterally at intervals corresponding to the spacing of the reflector surfaces. When the rod is installed on a backplane of the equipment, with a plurality of circuit cards projecting perpendicularly from the backplane, optoelectrical devices on the circuit cards are arranged to be in register with the inclined reflector surfaces. Optical signals transmitted along the optical busbar will be distributed to the circuit cards. The optical conductor will, of course, function with the light travelling in the opposite direction, i.e.