Numerical Study on Coherent O-Band Transmission for Data Center Campus Interconnects

The industry is moving toward higher data rate for dater center campus interconnect, i.e., 800G or higher. Intensity modulation direct detection technology based on 200G/lane has difficulty meeting the distance target of 10 km and hence, coherent transmission technology becomes an alternative to meet the need in this space. O-band coherent transmission is a potential approach for lower-cost and low power consumption for campus interconnect. We study the coherent transmission in O-band using LAN-WDM with one to four wavelengths at 800G/Lane for 10 km link distance. Detailed modelling is conducted to understand the limitations imposed by fiber nonlinearities, laser linewidth and equalization length on the power budget.