Effective coupling for multifiber connection into optical waveguides based on spherical lensed optical fibers

In this work, the possibility of implementing a non-contact transmission between telecom optical fibers and polymer optical waveguides is proposed. A low-loss coupling was achieved using a spherical lensed optical fiber fabricated by the electric arc method. The focal properties were proven, which resulted in the improvement of the coupling loss between the optical fiber and the waveguide with geometric mismatch. The optimal distance between them was determined to be 50 µm for the lensed fiber with a 180 µm diameter. The fabrication process of the multi-fiber connector with lensed optical fiber was shown. Two methods of connection were prototyped. For the complete connector, optical losses were equal to 1.25 ± 0.21 dB and 1.07 ± 0.15 dB, respectively, for 850 nm and 1300 nm wavelengths. On the other hand, for the minimalist version using only multi-fiber ferrule, the losses decreased to 0.98 ± 0.04 dB and 0.75 ± 0.06 dB for both wavelengths tested.