Net 300 Gbps/λ Transmission Over 2 km of SMF With a Silicon Photonic Mach-Zehnder Modulator

Employing our 47 GHz bandwidth silicon photonic (SiP) traveling wave Mach-Zehnder modulator (TW-MZM), we demonstrate the transmission of 134 Gbaud PAM-4 (net 250 Gbps) at a BER below the 6.7% overhead hard-decision forward error correction (HD-FEC) threshold of 3.8
$\times \,\,10^{-3}$
over 2 km of standard single-mode fiber (SSMF) in the O-band with only linear feed- forward equalizer (FFE). With the aid of non-linear pre-distortion and FFE, we transmit 115 Gbaud PAM-8 (net 288 Gbps) and net 305 Gbps PS-PAM-8 above the 19.02% overhead soft-decision FEC with a normalized general mutual information (NGMI) threshold of 0.8798. These results are the highest reported net rates for an all-silicon modulator in an intensity modulation direct-detection (IM/DD) system.