用光子扩展AI：光互连入门

Scaling AI with Photons: Primer on OpticalInterconnects Industry Overview As role of optics in AI grows, TAM reaches$73bn by CY30AI data center networking trends are accelerating towards higher bandwidth and data rate speeds (doubling every two years), low latency, dense clusters (100Ks of XPUs) fortraining and inference, longer distances (10m to 10km), andcomplex architectures forscale-out and scale-up domains. We believe these challenges put the opticalcommunications industry in a strong position to benefit, especially as optics increasinglypenetrates domains dominated by copper (e.g. scale-up) evidenced by multi-year supplydeals between NVDA and LITE/COHR in the multiple billions of revenue each. Ongoingand new growth drivers can fuel a $14bn optics market in CY25 to grow at a 39% CAGRto $73bn by CY30E which is 39% of the $245bn AI networking TAM. We highlight thevarious technologies, vendors and major trends across the landscape as immensedemand is leading to supply shortages and transforming supplier business models.What’s new and proprietary is our bottoms-up AI networking and connectivity modelwhich sizes key categories in switches, optical components and systems and copper. Transceiversare here to stay; 800G/1.6T cycles still earlyOptical transceivers have been an interconnect mainstay due to their pluggable form factor and practicality, flexible configuration, and strong performance at higher dataspeeds and distances. While concerns over compounding power consumption at scale isleading to questions about the module roadmap, we believe a vast majority of opticalports, especially in scale-out will be served by transceivers with the 800G cycle goingstrong into CY28 and 1.6T still at the cusp of a major inflection which can propel themarket from $13bn in CY25 to $45bn CY30 (29% CAGR) led by SiPho/EML modules. CPO and OCSopen up huge new growth vectorsWe expect co-packaged optics (CPO) to gain traction beginning in CY27 scaling to an entirely new $15bn TAM by CY30E for core components. NT traction will be in scale-out,but we believe the critical opportunity will be in scale-up which could take off in CY28and grow to a $9bn market as the copper dominated-network transitions into optical.Optical circuit switches (OCS) are another incremental driver as legacy switching infrareplacement, concerns about redundancy, and the need for scale-up (i.e. TPUs) driveadoption. We think OCS grows from $1bn today to $4bn by CY30E. Rising tide for the value chain:MRVL, COHR, LITE, etc.Unprecedented demand, tight supply with long capacity expansion lead times, contracting design cycles, andan increasing ability to differentiate provide a multi-yearrising tide. We highlight MRVL as a key beneficiary given its strong DSP market share as800G transitions to 1.6T. LITE is a key vendor in components given leadership in EMLand CW lasers, especially for CPO. COHR’s indium phosphide supply advantage helpsexpand share in transceivers and CPO. NVDA, AVGO, and MTSI also set to benefit. This research report provides general information only. No part of this report may be usedor reproduced or quoted in any manner whatsoever in Taiwan by the press or otherpersons without the express written consent of BofA Securities.>> Employed by a non-US affiliate of BofAS and is not registered/qualified as a research analyst under the FINRA rules.Refer to "Other Important Disclosures" for information on certain BofA Securities entities that take Contents What is LPO and LRO?12LPO/LRO TAM and key vendors12 The problem with optical transceivers13CPO superiority14Ecosystem buy-in noticeably improving15CPO market size (optical TAM)17CPO switching market size18CPO supply chain20 Optical Circuit Switches (OCS)27 AI Networking and Connectivity Model35 Glossary37 AI Semiconductor TAM Flow Chart Exhibit1:Within the $1.4 trillion AI data center semiconductor TAM and $246bn AI networking TAM by CY30E, we focus on the $73bn marketin optical andall its subcomponentsBofA CY30 AI TAM flow chart AI optical networking value chain Exhibit2:The supply chain for AI optical networking is expansive, spanning foundational tech providers (equipment, foundries, substrates), componentsuppliers, module makers, networking integrators, and hyperscaler end customersAI optical networking value chain Data center networking map Exhibit3:AI networking architectures consist of a back-end scale-up, back-end scale-out, front-end scale-out, and scale-across domainsDatacenter networking map Where copper can’t, optics is a must Copper is reliable, cheap, and low power, hence it maintains significant staying powerper the operator philosophy“copper if you can, optics if you must”for data centernetworking. However, as AI moves towards extremely large and dense clusters whereconnections intra-rack and multi-rack are extending in distance and bandwidth needs aresurging, basic copper solutions like DAC (direct attach copper) experience sharp electricsignal degradation a