Transmission of 273.6 Tb/s Over 1001 km of 15-Mode Multi-Mode Fiber Using C-Band Only 16-QAM Signals

In recent years, space-division multiplexing (SDM) has been proposed and investigated as a technique to increase the per-fiber capacity in order to cope with the ever-increasing demand for capacity in optical transmission networks. Considering the various SDM architectures proposed, multi-mode fibers potentially allow for the highest spatial channel density, but current demonstrations have been limited to mostly short-distance high-mode count or long-distance low-mode count transmission. In this work, we transmit 15 modes × 184 wavelength channels × 24.5 GBd PDM-16-QAM signals, spanning the full C-band, over 1001 km of 15-mode multi-mode fiber. The resulting net data rate of 273.6 Tb/s is the highest reported data rate in long-distance multi-mode fiber transmission and results in a record capacity-distance product of 273.9 Pb/s · km for multi-mode transmission. This was achieved by using mode multiplexers with low mode-dependent loss (MDL) and insertion loss, as well as a 15-mode fiber optimized for a low differential mode delay (DMD) transmission regime.