Equalizer-Free Transmission of 100-Gb/s 4-PAM Signal Generated by Flip-Chip Interconnection EADFB Laser Module

We fabricated a flip-chip interconnection lumped-electrode EADFB laser module and an optical receiver that includes a broadband electrical amplifier. Both have a 3-dB bandwidth of more than 50 GHz. Under 53.2-Gbaud 4-PAM (107 Gb/s) operation, clear eye openings were obtained without an equalizer even after a 2-km SMF transmission, and we obtained a BER of less than 2 × 10 −4 under error-free conditions using KP4 FEC without an equalizer also after a 2-km SMF transmission.