GOLDEN SUN SECURITIES·2025-12-14 08:22Investment Rating - The report maintains a "Buy" rating for key companies in the optical communication sector, including Zhongji Xuchuang, Xinyi Sheng, and Tianfu Communication [5][10]. Core Insights - The optical isolator is a critical passive device in optical communication systems, relying on the combination of polarizers and Faraday plates. There is a significant technological dependency and supply gap in the upstream manufacturing of these core components, particularly in high-end Faraday magnetic optical materials, which has become a bottleneck for industry development [1][19]. - The report highlights the low domestic production rate of core materials for polarizers, which are monopolized by Japanese and Korean suppliers, indicating a need for increased localization [3][21]. - The global shortage of Faraday plates is a critical issue, as their complex material growth and precision processing are dominated by a few companies in the US and Japan, leading to supply constraints that hinder the expansion of isolators and high-speed optical modules [4][22][23]. Summary by Sections Investment Strategy - The report suggests focusing on the upstream gaps in isolators, particularly polarizers and Faraday plates, and recommends companies like Zhongji Xuchuang, Xinyi Sheng, and Tianfu Communication for investment [8][24]. Market Review - The communication sector has seen an increase, with optical communication performing particularly well, as indicated by various indices showing significant growth [15][18]. Supply Chain Dynamics - In 2024, China's production capacity for polarizers is expected to account for approximately 73% of the global market, yet the localization rate of core materials remains below 10%, posing challenges to supply chain stability [6][7][24]. Key Companies to Watch - The report identifies several key companies to monitor within the optical communication and related sectors, including Zhongji Xuchuang, Xinyi Sheng, Tianfu Communication, and others involved in the supply chain [8][9][24].