Core Viewpoint - The article discusses the transition from copper cables to optical fibers in data center networks, emphasizing the advantages of optical technology, particularly CPO (Co-Packaged Optics), in supporting next-generation AI servers and addressing the challenges of mass production [2][11]. Group 1: Advantages of Optical Fiber over Copper - Optical fibers offer significantly higher bandwidth, capable of supporting 800G, 1.6T, and above, making them suitable for high-speed interconnect scenarios [3][5]. - The transmission speed of optical fibers is approximately two-thirds the speed of light, which reduces latency and enhances response times in data centers [3]. - Optical fibers can transmit data over much longer distances, with single-mode fibers reaching up to 100 kilometers, compared to copper cables, which typically support less than 10 meters for high-speed transmission [3][4]. - Optical fibers are more reliable, less affected by environmental factors and electromagnetic interference, ensuring stable data transmission in high-power environments like AI data centers [3][4]. - The space efficiency of optical fibers is superior, being thinner, lighter, and more robust, allowing for greater bandwidth in a smaller footprint [3]. Group 2: CPO Technology and Its Importance - CPO technology is identified as a key advancement for next-generation AI servers, integrating optical components directly into the packaging of ASIC/xPU chips, which enhances energy efficiency and bandwidth density [11][15]. - The CPO roadmap indicates a trend towards reducing the distance between optical engines and ASICs, with the industry currently in the commercialization phase of on-board optics [12]. - CPO significantly reduces signal loss and latency by shortening the transmission path between ASICs and optical devices from several centimeters to just a few millimeters [15]. - CPO can lower power consumption by up to 70% compared to traditional optical modules, as it minimizes the need for high-power digital signal processors [15]. Group 3: Challenges in CPO Mass Production - The complexity of packaging technology, including advanced techniques like hybrid bonding and 2.5D/3D packaging, poses challenges for ensuring system reliability and yield management [28]. - There are concerns regarding the performance of silicon-based photonic integrated circuits (PICs) compared to traditional modules using indium phosphide (InP) [28]. - Durability and thermal management are critical, as all optical components are tightly packaged within the ASIC/xPU system, requiring them to withstand high temperatures [28]. - Reliability issues arise from the close integration of optical engines with ASICs, where a single failure could jeopardize the entire high-cost system [28]. Group 4: Future Adoption and Market Trends - The adoption of CPO technology in switches is expected to occur around 2027-2028, particularly as the demand for higher bandwidth solutions increases [30]. - Major companies like Broadcom and NVIDIA are already developing their CPO solutions, indicating a competitive landscape for this technology [31][35]. - The transition of xPU systems to CPO is anticipated to be slower due to higher integration complexity and thermal management challenges, but it could lead to significant market growth in the long term [40].