Artificial Neural Network Equalizers for PAM-4 using DML-on-Silicon

Nonlinear equalizers (NLEs) based on artificial neural networks (ANNs) are studied for short-reach 4-level pulse amplitude modulation (PAM-4) transmissions [1,2] utilizing directly-modulated membrane lasers fabricated on silicon substrates (DMLs-on-Si) [3,4]. Using 28-GBaud signals over 2-km of single-mode fiber (SMF), we compare two ANN-NLEs with a previously developed reduced-complexity Volterra-NLE (VNLE) [5].