Distributed reservoir computing based nonlinear equalizer for VCSEL based optical interconnects

Abstract

We propose a distributed reservoir computing based nonlinear equalizer for 106 Gbps VCSEL based optical interconnects. By comparing with neural network and Volterra series based equalizers, the computational complexity of this proposed nonlinear equalizer is significantly reduced in the training, prediction and inference process. 106 Gbps PAM4 short-range optical transmission is demonstrated by experiment, using a VCSEL-based co-packaged optical transmitter to verify the performance of the equalizer and key parameters that affect the nonlinear compensation performance are carefully investigated. We believe that by incorporating such simplified nonlinear equalizers, it is possible to compensate for nonlinear impairments while preserving the inherent advantages of VCSEL-based optical interconnects. This optical interconnect will become a promising paradigm to overcome I/O performance penalty when communication leaving packages.