Applicability of Standard Cladding Diameter Multi-Core Fiber Cables for Terrestrial Field

In this paper, we investigate the deployment properties of step-index multi-core fibers (SI-MCFs) and trench-assisted multi-core fibers (TA-MCFs) in terrestrial high-density cables and links. We reveal that SI-MCFs and TA-MCFs can be designed with the same core pitch while maintaining their compatibility with conventional single-mode fiber (SMF) compliant with ITU-T Recommendation G.652. When SI-MCFs and TA-MCFs were implemented in high-density cables, we observed no significant increase in loss during the cabling and installation processes. Furthermore, the crosstalk deviation between processes is consistent with power coupling theory, indicating that effective bending is a key factor in determining the crosstalk under deployed conditions. We also confirm that good fusion splicing for MCF link connection is achievable by ensuring sufficient angular alignment accuracy. Additionally, our field experiments verify that accounting for the randomness of MCFs in the longitudinal direction of the link can reduce the characteristic deviation between MCF cores, leading to improved transmission characteristics.