Cascade Recurrent Neural Network Enabled 100-Gb/s PAM4 Short-Reach Optical Link Based on DML

A cascade RNN-based equalizer is proposed which outperforms traditional NN-based equalizers for short-reach optical links. A cascade RNN-enabled 100-Gb/s PAM4 link is experimentally demonstrated over 15-km fiber using a 16-GHz DML in C-band.