Optical interconnects on printed circuit boards using embedded optical fibers

The use of standard telecommunication components for optical communication over very short ranges (< 2 m) on and between printed circuit boards (PCB) is restricted due to their comparatively large dimensions and high price. For this reason efforts are made to reduce the size of the electrooptic and optoelectronic converters and to integrate optical waveguides into the board like common PCB tracks. In this paper we present a novel board level optical interconnect, based on standard multimode glass fibers, which are embedded into a multilayer PCB. The fibers are accessed through cavities inside the PCB by novel optoelectronic coupling elements. These elements combine laser- or photodiodes with coupling structures to achieve as a new feature a solely passive alignment. The objective is the automatic mounting of the components with common pick-and-place systems.