Core Viewpoint - Google discusses the future device technology for optical circuit switches (OCS), focusing on data center networks and machine learning supercomputers, highlighting the impact of device parameters on system performance and reliability [1][3]. Group 1: Introduction and Background - Large-scale systems rely on networks to transmit information from source to destination, primarily using electronic packet switches (EPS) and a fixed Clos topology, which face scalability limitations in cost, latency, and reconfigurability [3][5]. - Early research into OCS aimed to dynamically adjust network topology to match communication patterns, leading to practical deployments in large-scale data centers and machine learning systems [3][4]. Group 2: Future Optical Switching Technology - Table I outlines key performance metrics for commercial and developmental OCS technologies, including port count, switching time, insertion loss, and driving voltage, with variations based on whether the switching function is implemented in free space or guided-wave systems [7][8]. - Current commercial OCS devices are based on customized hardware and control schemes, with no single technology achieving optimal performance across all applications [9]. Group 3: Existing and Emerging Technologies - MEMS-based optical switches provide significant cost advantages in large-scale data center networks, enhancing system availability and performance [12]. - New device types, such as two-dimensional digital liquid crystal (DLC) pixel arrays, utilize polarization properties for light beam direction control, allowing for scalable port configurations [12][14]. - Development of two-dimensional devices primarily focuses on silicon photonics (SiP) technology, which is compatible with standard CMOS processes, aiming for lower costs and faster switching speeds [14][15]. Group 4: Challenges and Innovations - The Apollo project by Google aims to replace traditional network infrastructure with OCS, reducing communication delays and power consumption by keeping data in the optical domain [25][29]. - The OCS technology allows for significant reductions in power consumption, with maximum power usage at 108 watts compared to 3000 watts for traditional EPS systems [30]. - Google has deployed thousands of OCS systems, claiming it to be the largest application of OCS globally, with substantial cost and energy savings [31]. Group 5: Future Directions - Google is focused on developing OCS systems with higher port counts, lower insertion losses, and faster reconfiguration speeds, which are expected to enhance efficiency and reliability [36][38]. - The company believes that modern data centers can achieve bandwidth comparable to the entire internet, indicating the potential for massive communication volumes [38].