1.2 Pb/s Throughput Transmission Using a 160 $\mu$m Cladding, 4-Core, 3-Mode Fiber

This paper extends a recent demonstration of 1.2 Pb/s transmission using a few-mode multi-core fiber with a cladding diameter of 160 <inline-formula><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula>m. The fiber was a 3.37 km, 4-core, 3-mode few-mode multi-core fiber with spatial multiplexing and demultiplexing performed with especially designed mode-selective couplers. We transmitted 368 wavelength division multiplexed spatial super channels across the <italic>C</italic> and <italic>L</italic> bands. We selected polarization-division-multiplexed-256-quadrature amplitude modulation format to maximize the generalized mutual information of the transmitted signals, which were decoded using punctured soft-decision forward error correction with a code rate granularity of 0.01. The maximum crosstalk of the system was <inline-formula><tex-math notation="LaTeX">$-$</tex-math></inline-formula>31 dB between LP<inline-formula><tex-math notation="LaTeX">$_{11}$</tex-math></inline-formula> modes of adjacent cores, leading to a Q-factor penalty of approximately 0.5 dB. We estimated the system mode-dependent loss values ranging from 3 dB to 5 dB across <italic>C</italic> and <italic>L</italic> bands with negligible wavelength dependence.