Development of PAM-4 signaling for high performance computing, supercomputers and data center systems
We propose a new scheme for multilevel pulse amplitude modulation (PAM-4) signaling for optical interconnects and data center networks. Our approach is to use only one 4x4 multimode interference (MMI) structure with two phase shifters in push-pull configuration. An extreme high bandwidth and compact footprint can be achieved. The whole device is designed using the existing VLSI technology.