谷歌分享：光交换的下一步

Core Viewpoint - The article discusses the future device technologies for optical circuit switches (OCS), focusing on their application in data center networks and machine learning supercomputers, highlighting key performance parameters that affect system performance and reliability [2][4]. Group 1: Introduction and Background - Large-scale systems rely on networks to transmit information from source to destination, primarily using electrical packet switches (EPS) and a fixed Clos topology, which face scalability limitations in cost, latency, and reconfigurability [4]. - The exploration of optical circuit switches (OCS) aims to dynamically adjust network topology to match communication patterns, leading to their deployment in large-scale data centers and machine learning systems [4][6]. Group 2: Future Optical Switching Technologies - Table I outlines key performance metrics for various commercial and developmental OCS technologies, including port count, switching time, insertion loss, and driving voltage, which vary based on whether the switching function is implemented in free space or guided-wave structures [8][9]. - Current commercial OCS devices are based on customized hardware and control schemes, with no single switch technology achieving optimal performance across all applications [10]. - MEMS-based optical switches provide significant cost advantages in large-scale data center networks and enhance system performance when used in TPU superpods [13]. Group 3: Device Technologies - Emerging device technologies include non-mechanical two-dimensional digital liquid crystal (DLC) pixel arrays, which control light beam propagation direction using polarization characteristics [13]. - Two-dimensional devices are primarily based on cross-matrix structures with waveguides, with silicon photonics (SiP) technology being a focus for achieving lower costs and faster switching speeds [16]. - Challenges for two-dimensional switches include high losses during fiber coupling and limited port counts, with interference-based devices and heterogeneous integrated devices being explored to address these issues [16][17]. Group 4: Conclusion - As optical circuit switching technology commercializes, research activities around future optical switch device technologies are rapidly increasing, with expectations for some developmental technologies to be introduced into future computing and networking systems for mass production [22].