Self-Homodyne Coherent Detection Transmission Through a (1+8) Multicore Fiber With One Polarization-Maintaining Core

We propose and experimentally verify a self-homodyne coherent (SHC) transmission scheme based on a 1+8 multicore fiber with one polarization-maintaining central core and eight ordinary single-mode cores. The 1+8 multi-core fiber can take advantage of SHC by reducing the path mismatch introduced by the fiber, and does not require an additional polarization control unit. Since it provides 8 spatial channels under the 150 μm fiber cladding diameter, the optical capacity density per unit area has been improved. The fabrication process of the 1+8 multi-core fiber and the fan-in/fan-out device corresponding to the fiber are described. Finally, we successfully demonstrate real-time 6.4 Tbps (8 × 800G) SHC transmission by using this multicore fiber. The system allows the use of a high-powered distributed feedback (DFB) laser and reduces the complexity of digital signal processing (DSP). This study shows that using multicore fiber is an attractive solution for future co-packaged optical-IO switching applications.