Transmission of 30-GBd polarization-multiplexed probabilistically shaped 4096-QAM over 50.9-km SSMF

We demonstrate the transmission of a 30-GBd polarization-multiplexed probabilistically shaped 4096-ary quadrature amplitude modulation (QAM) signal over 50.9-km standard signal-mode fiber (SSMF), with a net single-carrier bit rate of 484.4 Gb/s carrying 16.1 information bits per symbol (a potential spectral efficiency of 15.9 bits/s/Hz when taking into account a 0.01 spectral roll-off). The signal is generated from 28-nm complementary metal-oxide-semiconductor (CMOS) digital-to-analog converters (DACs) with 8-bit nominal resolution and is received by an intradyne coherent receiver with a laser that has a linewidth of ∼1 kHz.