Compact multi-fiber receptacle interface for on-board optical interconnection

We have developed a new type of receptacle interface that enables us to achieve dense multi-fiber connection between a planar lightwave circuit based optical device and single-mode fibers on a printed circuit board. To obtain both a small size and good optical performance with this interface we devised a small fiber guide for aligning the fibers with waveguides, and also developed a refractive-index-matching gel that maintains stable optical performance. We fabricated sufficiently small (5 mm long) 32-fiber interfaces, and successfully obtained low connection and high return losses with average values of 0.17 and 60 dB, respectively. We also demonstrated that the interface can provide sufficient environmental durability. Our new interface eliminates the need for pigtail fibers on the board, and this will lead to the development of dense and low-cost optical interconnection on a board for advanced optical network systems.