That is usually done for permanent connections, but it may be possible to dismantle a splice without spoiling the fiber ends. Multi-core optical fiber, with its ability to transmit multiple signals simultaneously, has emerged as a promising solution to meet this demand. Additionally, due to its characteristics such as multi-channel transmission, high integration, spatial flexibility, and versatility, multi-core optical. Optical fibers can be joined together, such that light is efficiently transferred from one fiber to another. Fusion splicing is the most widely used method of splicing as it provides for the lowest loss and least reflectance, as well as providing the strongest and most reliable joint between two fibers. Fiber misalignment and fiber geometry mismatch (e., core size, core-to-clad concentricity, core and cladding non-circularity, numerical aperture, etc. However, differences in the backscattering coefficients between two fibers can also show up. To address this, Sumitomo Electric Industries, Ltd. Since the very beginning of the SDM R&D, we have continuously contributed both to revealing the behavior and. Lightera Multicore Optical Fiber is an innovative approach to fiber design and has the potential to revolutionize the way data is transmitted, improving speed, efficiency, and performance.