We investigate the scalability and performance of a novel optical wireless data center network (OW-DCN) based on passive diffractive optics and fast tunable transmitters. The proposed OW-DCN architecture consists of two parallel inter- and intra- cluster networks to implement a flat communication between the top of racks within the DCN with at most two hops. The proposed DCN operation, the transmission performance and the scalability have been experimentally demonstrated and assessed for different modulation formats (NRZ-OOK and PAM4) with different sizes of DCN. A DCN with $8\times 8$ racks shows 20Gbit/s OOK error free transmission with a power penalty of only 1dB compared to the B2B performance. For a $16\times 16$ racks DCN, experiment indicates 16Gbit/s PAM4 transmission at FEC-limit of $\text {BER} < 2\times 10^{-3}$ . Moreover, scalability investigations of the proposed DCN architecture with optimized passive optics indicate that a $32\times 32$ racks DCN with spectral band around 1 nm per link is feasible.

中文翻译：

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数据中心网络中光无线技术的可行性研究

我们研究了基于无源衍射光学和快速可调发射器的新型光学无线数据中心网络 (OW-DCN) 的可扩展性和性能。所提出的 OW-DCN 架构由两个并行的集群间和集群内网络组成，以实现 DCN 内机架顶部之间最多两跳的平面通信。所提出的 DCN 操作、传输性能和可扩展性已经针对具有不同 DCN 大小的不同调制格式（NRZ-OOK 和 PAM4）进行了实验证明和评估。DCN 与 $8\乘以8$ 机架显示 20Gbit/s OOK 无错误传输，与 B2B 性能相比，功率损失仅为 1dB。为一个 $16\乘以16$ 机架 DCN，实验表明 FEC 限制为 16Gbit/s PAM4 传输 $\text {BER} < 2\times 10^{-3}$ . 此外，所提出的具有优化无源光学器件的 DCN 架构的可扩展性研究表明 $32\乘以 32$ 机架 DCN 的光谱带约为每链路 1 nm 是可行的。