Optical interconnection schemes using micro-optic connectors for passive packaging in optical PCBs

Two types of fiber-embedded micro-optic connectors were proposed for passive packaging in the optical PCB. In the first type, 1 × 12 silica optical fibers having 100/110 μm core/cladding diameters were bent by 90-degree and mounted in a tetragonal body with a ∼3 × 3 × 5 mm² size. The measured bending losses of the fibers were -0.61 dB, -0.46 dB, and -0.21dB when the radii of curvature are 1.0 mm, 1.5 mm, and 2.0 mm, respectively. The side and bottom surfaces of the tetragonal block were mechanically polished to reveal smooth apertures at the ends of the fibers. In the second type, a plastic fiber bundle was bent by 90° and mounted also in a tetragonal body with a millimeter scale size. The core sizes of the individual fibers in the bundle were about 10 μm and 20 μm, and the diameters of the bundle were about 0.55 mm and 1 mm, respectively. The bending loss of the 90°-bent fiber bundle was approximately -0.8 dB for 0.55 mm diameter and -1.4 dB for 1 mm diameter with a curved radius of ∼1.5 mm. This fiber bundle block can provide a very large tolerance above several hundred micrometers in the alignment in vertical and lateral directions between the connector and the optical layers in OPCBs. We have successfully demonstrated 2.5 Gb/s data link assembling both types of connectors in the fiber-embedded PCBs.