Extremely low-loss and bendable tapered multi-core fiber with double core structure for compact assembly of Silicon Photonics multi-port devices

摘要

We are investigating to utilize multi-core fiber for increasing the concentration of optical fiber and the density of optical connector. Until now. from the viewpoint of optical mounting, the bending loss and the crosstalk of the multi-core fiber in a short distance range have not been investigated so much. In this report, we propose low-loss and easily bendable multi-core fiber with a novel double core taper structure to realize highly efficient optical coupling to a silicon photonics integrated circuit, and compact fiber mounting with small bending radius. By BPM simulation, we confirmed that it is possible to suppress the bending loss of less than 0.5 dB and the inter-channel crosstalk to -20 dB or less when the radius of curvature is 3 cm. Based on this result, we fabricated an optical fiber with the double core taper structure in order to verify the characteristics. As a result, the coupling loss was realized within 1.5 dB with low radiation loss. It is therefore considered that the double core taper structure can be sufficiently applied to the multi-core fiber.