Intra-Data Centre Flexible PAM Transmission System Using an Integrated InP-Si3N4 Dual Laser Module

Flexible Pulse Amplitude Modulation (FlexPAM) consists of the use of non-standard PAM formats, such as PAM-5 or PAM-6, to increase the granularity of the link capacity for a given baud rate. In this paper, we demonstrate FlexPAM systems as a scalable solution for future data center interconnects, introduce a symbol-to-bit mapping that minimizes the effect of intensity noise in the performance of non-power of two number of levels formats, and present experimental and simulation results of an unamplified FlexPAM transmission system over 1 km of single-mode fiber. 20 GBaud transmission was successfully demonstrated experimentally for modulation formats ranging from OOK up to PAM-16 using an integrated InP-Si
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laser. In addition, a simulation to closely replicate the experiment was used to determine the system requirements to achieve transmission rates of up to 200 Gbps on a single wavelength, at a baud rate of 53.5 Gbaud with component bandwidth limitations of 30 GHz.