Cost Estimation of Space-Division- Multiplexing Fibers

We estimate the costs of multi-core single-mode fibers (MCFs) and single-core few-mode fibers (FMFs) for spacedivision multiplexing, taking into account their specific designs, manufacturing processes, and measurement procedures. Based on the current state-of-the-art MCF preform capacity of 2,000km (vs 10,000km for a single-mode-fiber (SMF) preform with a standard germanium-doped step-index core), we show that MCF cost per core is ≤1.25× that of SMF for up to 7 cores, assuming a realistic core yield of ∼94%. Looking ahead, if MCF preform capacity can be increased to ∼3,400km, MCF cost per core could match that of SMF for up to 7 cores. Finally, while the costs of MCFs with 12 cores may become manageable with realistic improvements in yield and/or preform capacity, MCFs with more cores do not yet appear cost-effective. As for FMFs, we show that cost per mode is lower than that of SMF for yields ∼60%, a level that is currently achievable. Although some of our assumptions may require further refinement, the cost sensitivity analysis across various process-dependent parameters indicates that our main conclusions are robust to variations in manufacturing processes and measurement methods. Moreover, the methodology presented here is adaptable to a broad range of core and cladding structures, including variations in refractive index profiles and dopant compositions. These cost estimations for SDM fibers provide a more accurate basis for evaluating potential cost-per-bit improvements in SDM systems, while also considering additional expenses related to transponders, repeaters, cables, fan-in/fan-out devices or mode (de)multiplexers, and deployments. This could ultimately pave the way for their broader adoption.