Mode-division-multiplexing self-homodyne coherent transmission over a weakly coupled few-mode fiber for optical interconnections

Self-homodyne coherent transmission has recently received extensive investigation as a coherent lite candidate for highspeed short -reach optical networks. In this Letter, we propose a weakly coupled mode -division -multiplexing (MDM) self-homodyne coherent scheme using a multiple -ring -core few -mode fiber, in which one of the modes transmits a selfhomodyne local oscillator (LO) and the rest are utilized for carrying signals. Multiple rings of index perturbations in the fiber core are applied to achieve low modal crosstalk, allowing the signals and the remote LO to be transmitted independently. We experimentally demonstrate a 7.2-Tb/s (5.64-Tb/s net rate) self-homodyne coherent transmission with an 800Gb/s data rate for each of the nine information -bearing modes formatted in 80-GBaud probabilistic constellationshaped 64-quadrature-amplitude modulation. To the best of our knowledge, this is the first experimental demonstration of an MDM self-homodyne coherent transmission with up to 10 spatial modes. The proposed scheme may pave the way for future high -capacity data center interconnections. (c) 2024 Optica Publishing Group