通信行业周报：光模块：1.6T放量在即，上游再趋紧

Investment Rating - The report maintains a "Buy" rating for key companies in the optical module sector, specifically recommending companies like Zhongji Xuchuang and Xinyi Sheng [13]. Core Insights - The 1.6T optical module is entering a phase of large-scale release in 2026, with upstream core components (DSP, EML, silicon photonics capacity, and isolators) facing a tightening supply situation [22][28]. - The DSP market is dominated by a duopoly of Broadcom and Marvell, with advanced process capacity becoming a bottleneck due to high demand from AI chips [23][28]. - EML chips are primarily led by overseas companies like Sumitomo, while domestic firms are accelerating to fill the supply gap [24][27]. - The silicon photonics sector is seeing increased penetration, with a diverse design landscape and critical reliance on foundry capacity [25][28]. - Isolators are becoming a hidden bottleneck in the delivery of high-speed optical modules due to their essential role in preventing damage from reflected light [26][32]. Summary by Sections Optical Module Market - The 1.6T optical module is set for large-scale production, driven by the evolution of AI computing clusters towards higher density [22]. - Supply constraints are emerging for core components, particularly DSPs, which are critical for high-speed signal recovery [28]. DSP Market - The DSP market is characterized by a duopoly, with Broadcom and Marvell controlling the majority of the supply for 1.6T DSPs [23]. - Advanced process nodes (5nm and 3nm) are creating significant barriers to entry, with TSMC's capacity being heavily allocated to AI chip production [23][28]. EML Market - The EML chip market is currently dominated by Japanese firms, but domestic companies are rapidly advancing to meet the growing demand [24][27]. Silicon Photonics - The silicon photonics segment is experiencing accelerated growth due to its high integration and cost advantages, with a focus on both design and foundry capabilities [25][28]. Isolators - Isolators are becoming increasingly critical in high-speed optical modules, with their production facing challenges due to material dependencies and manufacturing complexities [26][32]. Investment Recommendations - The report suggests focusing on companies within the optical module supply chain, particularly those with strong capabilities in silicon photonics and EML production, such as Zhongji Xuchuang and Xinyi Sheng [10][16].