A wafer-level glass photonic interconnect technology triggered a single-day plunge of over 6% in the A-share CPO concept sector, prompting a large-scale repricing of capital across the optical communication industry chain.
On the morning of June 26th, the A-share CPO concept sector plummeted more than 6%, with major players like Zhongtian Technology, FiberHome Telecommunication Technologies, and Yongding Co., Ltd. hitting the daily limit-down. The immediate catalyst for this decline was the "Glass Bridge" glass photonic interconnect platform launched by the American optical fiber giant Corning at the "AI Data Center Optical Communication Interconnect Technology Conference" in Seoul, South Korea, on June 24th. The market is concerned that this technology, which uses wafer-level preformed glass optical waveguides to achieve passive alignment between optical fibers and photonic chips, could significantly simplify the fiber array unit (FAU) and precision active coupling equipment relied upon by traditional CPO architectures. This simplification poses a long-term risk of demand contraction for related midstream components.
Simultaneously, stocks related to glass substrates bucked the market trend and surged. Kaisheng Technology briefly hit the daily limit-up, DR Laser rose over 9%, Hongxing Development gained more than 8%, and Rainbow Display increased over 5%. Capital is flowing out from the CPO and PCB midstream manufacturing segments and shifting towards the glass substrate theme. This indicates a structural shift in the value focus of next-generation AI optical interconnects, with a pronounced "seesaw" market dynamic.
So, how exactly does this "Glass Bridge" technology, which caused such a deep market reaction, operate? Official technical documentation from Corning provides a systematic explanation.
Understanding the CPO Sector Plunge: The Impact Rationale of Glass Bridge
The core reason triggering the CPO sector's decline lies in the potential substitution effect of Glass Bridge on the existing supply chain structure.
In traditional co-packaged optics (CPO) architectures, the coupling between optical fibers and photonic integrated circuits (PICs) primarily relies on fiber array units (FAUs) and precision active alignment equipment. This step involves complex processes and high manufacturing costs, representing the core value for many A-share CPO supply chain companies.
The Glass Bridge released by Corning uses wafer-level glass ion exchange (IOX) waveguides to achieve passive alignment coupling between fibers and PICs, eliminating the need for active alignment equipment. The market consequently fears that if this solution achieves mass production in high-density scenarios, demand for traditional FAUs and lens coupling components could face long-term decline, thereby weakening the competitive moat of existing CPO midstream manufacturers.
Operational Mechanics of Glass Bridge: Three Core Technical Features
Corning's official documentation positions Glass Bridge as a fiber-to-PIC connector platform for next-generation optical architectures, supporting three application scenarios: near-packaged optics (NPO), co-packaged optics (CPO), and high-density photonic modules. Its technical framework is built on three core features.
Wafer-level manufacturing enables production consistency. The core components of Glass Bridge are produced using wafer-level manufacturing processes, utilizing glass ion exchange waveguides for passive alignment. This means the coupling between fibers and PICs requires no active calibration process. This design reduces manufacturing complexity while supporting consistent optical integration at high volumes, which Corning identifies as a key foundation for achieving cost-effective mass production.
Standardized TMT physical contact interface. Glass Bridge employs a standard TMT ferrule to create a re-pluggable physical contact connection interface, allowing for more natural integration with the existing optical ecosystem while supporting reliable, maintainable connections. The standardized interface lowers the integration barrier for system designers, indicating that the platform is not a complete disruption of the existing ecosystem but rather an expansion of capabilities based on current standards.
Detachable high-density connector architecture. Glass Bridge is designed as a detachable connector platform. A single connector supports over 24 optical channels and offers customizable pitch configurations to adapt to different systems and PIC requirements. The detachable design provides greater flexibility during assembly, testing, and system integration, accommodating the needs for rework and flexible adjustments in the manufacturing process of high-density optical systems.
Comparison with Traditional FAU Solutions: A Supplement, Not a Full Replacement
In its official FAQ, Corning clearly addressed the relationship between Glass Bridge and traditional FAU solutions. It stated that traditional fiber array units remain widely effective in current applications, but their assembly and scaling complexity increases significantly in scenarios requiring extremely high fiber counts. Glass Bridge is positioned as a "supplement" to FAU solutions, offering a wafer-level passive alignment alternative path to support higher density, greater scalability, and detachable system integration.
This statement somewhat tempers the market's extreme expectations of a "complete replacement," but does not alter the direction of the technological trend. As AI data centers demand ever-higher optical interconnect density, the applicability of traditional FAUs in the highest-density scenarios will gradually narrow. The wafer-level solution represented by Glass Bridge is stepping in to fill this space.
Value Chain Restructuring: Capital Shifts from CPO to Glass Substrates
The market's reaction to Glass Bridge extends beyond a single technological event, triggering a re-evaluation of the value distribution within the AI optical interconnect industry chain.
Analysts suggest that glass substrates are seen as the next-generation core material for advanced packaging, surpassing current silicon interposers and organic substrates. Amid surging demand for high-frequency signals, high integration, and large-size packaging from AI computing chips, and against the backdrop of domestic manufacturers facing patent barriers for silicon-based substrates, glass substrates have become a critical window for China's advanced packaging industry to achieve differentiated breakthroughs. Currently, glass substrate and through-glass via technologies are at a crucial juncture for industrial breakthrough, with AI computing demand providing ample momentum for commercialization.
Capital flows confirm this logic shift. Glass substrate concept stocks like Kaisheng Technology, DR Laser, Hongxing Development, and Rainbow Display collectively strengthened, forming a stark contrast with the CPO sector. Market sentiment is shifting from the manufacturing segment of midstream optical components and modules towards more upstream specialty materials. The industrial value center of next-generation AI optical interconnects is being reshaped.
Comments