title: Single-lane 180  Gbit/s PAM-4 signal transmission over 2  km SSMF for short-reach applications.
abstract: We experimentally demonstrate the generation and transmission of a single-lane 180  Gbit/s (90 GBaud) four-level pulse-amplitude modulation (PAM-4) signal in an intensity-modulation direct-detection system with a 7.5 GHz 3 dB bandwidth. The generated signal is transmitted over a 2 km standard single-mode fiber with, to the best of our knowledge, the highest reported net data rate in the C-band: 150  Gbit/s. A net data rate of 168  Gbit/s is also reachable with 1 km reach. The PAM-4 and duobinary (DB) PAM-4 modulation schemes are compared; the obtained results show that DB-PAM-4 significantly outperforms PAM-4 in the considered strong bandwidth-constrained system. Both a feed-forward equalizer and a maximum-likelihood sequence estimator are investigated for data recovery.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Stojanovic
authors.forename: Cristian
authors.initials: C
authors.lastname: Prodaniuc
authors.forename: Changsong
authors.initials: C
authors.lastname: Xie
authors.forename: Michael
authors.initials: M
authors.lastname: Koenigsmann
authors.forename: Piotr
authors.initials: P
authors.lastname: Laskowski