Connecting Silicon Photonic Circuits to Multicore Fibers by Photonic Wire Bonding

Photonic wire bonding is demonstrated to enable highly efficient coupling between multicore fibers and planar silicon photonic circuits. The technique relies on in-situ fabrication of three-dimensional interconnect waveguides between the fiber facet and tapered silicon-on-insulator waveguides. Photonic wire bonding can easily compensate inaccuracies of core placement in the fiber cross-section, does not require active alignment, and is well suited for automated fabrication. We report on the design, on fabrication, and on characterization of photonic wire bonds. In a proof-of-principle experiment, a four-core fiber is coupled to a silicon photonic chip, leading to measured coupling losses as small as 1.7 dB.