Low-Loss Highly Tolerant Flip-Chip Couplers for Hybrid Integration of Si 3 N 4 and Polymer Waveguides

In this letter, low-loss and highly fabrication-tolerant flip-chip bonded vertical couplers under single-mode condition are demonstrated for the integration of a polymer waveguide chip onto the Si3N4/SiO2 passive platform. The passively aligned vertical couplers have a lateral misalignment between polymer and Si3N4 waveguide cores of ±1.25 μm. Low-loss operation has been experimentally demonstrate...