A Comparative Study of Few-Mode Fiber and Coupled-Core Multi-Core Fiber Transmission

Few-mode fibers and coupled-core multi-core fibers are attractive transmission media for space-division multiplexed transmission systems as they enable a high spatial channel multiplicity whilst sustaining the current standard cladding diameter. This paper compares space-division multiplexed recirculating loop transmission using either a 3-mode few-mode fiber or a 3-core coupled-core multi-core fiber. After analyzing the spectral attenuation properties of both fibers, we investigate the wavelength and transmission distance dependence of the transmission channel characteristics. We find that the channel memory length is shorter and mode-dependent loss is lower in the coupled-core multi-core fiber, which can be attributed to the fundamental mode-structure differences between the two fiber types. This leads to a higher data rate at similar transmission distance for the coupled-core multi-core fiber.