Design of data center free-space optical network: Optical and mechanical considerations

Firefly, a flexible and wireless datacenter network based on free space optical links (FSO), can be used to overcome the traditional wired datacenter architecture, saving working cost, and potentially reduce cooling energy cost. Free space optical link performance contribute to the network efficiency while influenced by its optical design and working environment. Especially influence by the thermal condition inside datacenter. A well designed optical link with robust for different thermal working environments will provide steady communication performance. In this work, starting from thermal mechanic view, several factors that influence the link robust been studied including hot isle and cold isle, a galvo mirror based free space optical wireless link prototype had been designed and built up, software simulation been given to predict the system performance under different temperature and compare with the short distance experiment data, the result shows the free space optical link performs well at steady 10Gbps bandwidth with specific thermal environments. This work shows a good working robust for thermal environment influence could achieved by a proper optical design.