2 × 53 Gbit/s PAM-4 Transmission Using 1.3 μm DML With High Power Budget Enabled by Quantum-Dot SOA

We investigate the performance of $1.3~\mu $ m directly modulated multiple-quantum-well strained AlGaInAs distributed feedback laser in an optically amplified wavelength-division multiplexed (WDM) system for next-generation passive optical networks. We experimentally demonstrate $2\times 53$ Gbit/s PAM-4 transmissions over 20 km of a single-mode fiber employing two 16-GHz bandwidth-limited directly-modulated lasers and compare the performance of quantum-well and quantum-dot semiconductor optical amplifiers (SOAs) in amplifying DWDM links. We successfully obtained the total power budget of 34 dB for each WDM channel using a quantum-dot SOA and 30-tap T-spaced feed-forward equalizer.