英伟达详解CPO，光芯片闪耀Hotchips

Core Viewpoint - The article discusses advancements in optical chip technology presented at the Hot Chips 2025 conference, highlighting innovations from companies like NVIDIA, Celestial AI, and Ayar Labs, which aim to enhance data center performance and efficiency through silicon photonics and optical interconnects [2][75][236]. Group 1: NVIDIA's Innovations - NVIDIA emphasizes the need for co-packaged optics to significantly enhance AI factory scalability, noting that AI factories consume approximately 17 times more optical power than traditional cloud data centers [3][5]. - The Spectrum-X Ethernet technology aims to reduce the cost of network photonics, which constitutes about 10% of the total computing power cost in AI factories [3][16]. - Spectrum-X Ethernet photonics is claimed to be the first to implement 200 G/channel SerDes technology, improving signal integrity and reducing power consumption by decreasing the number of lasers required for high-speed links [16][34]. Group 2: Celestial AI's Photonic Fabric - Celestial AI showcases its Photonic Fabric module, which utilizes optical connections to link next-generation GPUs and accelerators, moving away from traditional electrical connections [75][78]. - The company is developing its own optical MAC (OMAC) to achieve high energy efficiency by matching SerDes with channels [80][92]. - Celestial AI's technology aims to optimize the integration of optical I/O within chip designs, enhancing performance and reducing power consumption [92][94]. Group 3: Ayar Labs' Optical I/O Solutions - Ayar Labs introduces a UCIe optical I/O retimer, designed to facilitate the integration of optical I/O into chip packaging, achieving data rates of up to 8 Tbps [108][122]. - The company addresses the challenge of scaling interconnects for large clusters of chips, which is critical for AI applications [111][117]. - Ayar Labs' technology aims to decouple optical and electrical signal transmission, allowing for larger systems compared to traditional electrical I/O [162][169]. Group 4: Lightmatter's Passage M1000 - Lightmatter presents the Passage M1000, which integrates co-packaged optics and silicon photonics, promising bandwidths of up to 114 Tbps [170][184]. - The design focuses on compact optical I/O, utilizing silicon micro-rings for efficient modulation [191][196]. - Lightmatter aims to enable optical circuit switching for redundancy and scalability in high-performance computing environments [211][224]. Group 5: OpenLight's Photonic Solutions - OpenLight Photonics aims to accelerate the transition to silicon photonics with its proprietary photonic application-specific integrated circuits (PASIC), designed for high-density, low-power optical interconnects [234][236]. - The company emphasizes customization in its PASIC offerings, allowing clients to tailor components to specific applications, enhancing flexibility in rapidly evolving markets [237][239]. - OpenLight's technology is positioned to address the growing demand for faster data transmission in AI data centers, with plans to expand its component library and production capabilities [238][239].