4-Level Alternate-Mark-Inversion for Reach Extension in the O-Band Spectral Region

• DOI: 10.1109/jlt.2021.3062446
• Publication Date: 2021-02-26T20:51:45Z
• Authors: Natsupa Taengnoi; Kyle R. H. Bottrill; Yang Hong; Naresh K. Thipparapu; Cosimo Lacava; Jayanta K. Sahu; David J. Richardson; Periklis Petropoulos
• Keywords: O-band reach extension; 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; Alternate-mark-inversion; intensity-modulation direct-detection; optical fibre transmission; 620

Alternate-mark-inversion (AMI) has been used in the past to improve the transmission performance of binary intensity modulation formats. In this work, we improved the tolerance of O-band 4-level pulse amplitude modulation (PAM4) transmission to channel impairments through the adoption of an AMI scheme. Improvements in receiver sensitivity were shown in both semiconductor optical amplifier (SOA) and bismuth-doped fibre amplifier (BDFA) equipped links. We confirmed the capability of 4-level AMI to extend the reach in the O-band, which was achieved through the mitigation of nonlinear and dispersive effects. We experimentally demonstrated a 4.28-dB Q-factor improvement for transmission over 60 km of SMF-28e. To offer an insight to the mechanisms leading to the improved tolerance to transmission impairments, we presented numerical simulations that illustrate the underlying method of action of AMI4.