Abstract

With millions of optical links deployed in a typical Data Center (DC) network, telemetry is becoming increasingly important, especially as the number of links and transmission bandwidths rise over time. Multi-path interference (MPI) arising out of multiple optical reflections from fiber connectors, transmitters and receivers is one optical impairment that has been known to cause performance degradation of links in the DC. Through monitoring the statistics of each pulse amplitude modulation (PAM) level at the receiver, we propose and experimentally demonstrate a digital signal processing (DSP) based method to detect the presence of a high level of MPI in intensity modulation direct detection (IMDD) networks. Having this information at hand, the fiber path can be cleaned before an optical link is degraded or fails, which can prevent misdiagnosis and can save time and effort spent on triaging after failure.

Mitigation of optical multipath interference impact for directly detected PAMn system

Yang Jing Wen, Yan Cui, and Yusheng Bai
Opt. Express 28(25) 38317-38333 (2020)

Fast QoT estimation method using cascaded artificial neural network for real-time path provisioning in IMDD based all-optical networks

Ryo Igarashi, Ryo Koma, Kazutaka Hara, Jun-ichi Kani, and Tomoaki Yoshida
Opt. Express 32(2) 1176-1187 (2024)

Adaptive decision threshold for an optical multipath-interference-impaired short-reach 50-Gbps PAM4 transmission

Yibin Li, Zixian Wei, Bohua Deng, Zhongxu Liu, Changyuan Yu, and H. Y. Fu
Opt. Lett. 48(21) 5675-5678 (2023)

Experimental demonstration of advanced modulation formats for data center networks on 200 Gb/s lane rate IMDD links

Jinlong Wei, Talha Rahman, Stefano Calabrò, Nebojsa Stojanovic, Liang Zhang, Changsong Xie, Zhicheng Ye, and Maxim Kuschnerov
Opt. Express 28(23) 35240-35250 (2020)

Improved transmission performance of adaptively modulated optical OFDM signals over directly modulated DFB laser-based IMDD links using adaptive cyclic prefix

E. Giacoumidis, J. L. Wei, X. Q. Jin, and J.M. Tang
Opt. Express 16(13) 9480-9494 (2008)