Abstract
Experimental demonstration is given of a real-time flexible downstream 50 Gb/s passive optical network (PON) mixed with 25 Gb/s or 100 Gb/s signals. 25 Gb/s transmission is enabled by using 25 Gb/s Miller encoding. For back-to-back a lower sensitivity for 25 Gb/s Miller of ${\sim}{2.2}\;{\rm dB}$ is found relative to 50 Gb/s non-return-to-zero (NRZ). An extended reach of 40 km and up to ${\sim}{5}\;{\rm dB}$ optical power budget improvement after worst-case 20 km standard single-mode fiber over 50 Gb/s NRZ was shown for 25 Gb/s Miller. It was also shown that optical network units (ONUs) that have 9 dB additional optical received power because they experience a lower optical loss can receive 100 Gb/s four-level pulse amplitude modulation (PAM4) instead of NRZ in a flexible rate PON, which will double the bit-rate to these ONUs. 50 Gb/s NRZ transmission under mixed modulation (50% NRZ and 50% Miller or 50% PAM4) can operate with very low penalty. A power penalty of ${\lt}{0.4}\;{\rm dB}$ was found for 50 Gb/s NRZ after worst-case total dispersion (as specified in ITU-T G.9804) when mixed with 25 Gb/s Miller or 100 Gb/s PAM4. For back-to-back there was a smaller penalty of ${\lt}{0.2}\;{\rm dB}$ for 50 Gb/s NRZ under mixed modulation. The 25 Gb/s Miller signal spectrum is similar to 50 Gb/s NRZ and 100 Gb/s PAM4, which enables good performance of the real-time clock and data recovery with an integrated adaptive feed-forward-equalizer based equalizer under mixed signal modulation. The increased optical power budget enabled by the 25 Gb/s Miller encoding effectively improves power margins of the high-speed PON and will enable reliable transmission for ONUs deployed with out-of-spec (higher) loss and/or (larger) fiber reach. The additional margin provided by 25 Gb/s Miller encoding will also enable a safe-mode for ONUs that experience out-of-spec scenarios because of faults in the PON fiber network.
© 2023 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Rene Bonk, Ed Harstead, Robert Borkowski, Vincent Houtsma, Yannick Lefevre, Amitkumar Mahadevan, Dora van Veen, Michiel Verplaetse, and Sheldon Walklin
J. Opt. Commun. Netw. 15(8) 518-526 (2023)
Ricardo Rosales, Ivan Cano, Derek Nesset, Romain Brenot, Natalia Dubrovina, Elena Durán-Valdeiglesias, and Helene Debregeas
J. Opt. Commun. Netw. 13(8) D13-D21 (2021)
Jialiang Jin, Dezhi Zhang, Qizheng Li, Mingbo He, Yuanfeng Mao, Qihong Wu, Zeru Wu, Xu Wang, Zhen Dong, Yanbo Li, Zhicheng Ye, and Jian Jian
J. Opt. Commun. Netw. 15(10) 726-735 (2023)