On the morning of June 26th, the A-share CPO concept sector plunged over 6%, with stocks like "Yi Zhongtian" falling across the board. Zhongtian Technology, FiberHome Telecommunication Technologies, Yongding Co., Ltd., and others saw their shares hit the daily limit down.
The immediate trigger for this round of decline was the Glass Bridge optical interconnect platform released by U.S. fiber optic giant Corning at the "AI Data Center Optical Interconnect Technology Conference" in Seoul, South Korea, on June 24th.
The market is concerned that this technology, which uses wafer-level prefabricated glass optical waveguides to achieve passive alignment between optical fibers and photonic chips, will significantly simplify the Fiber Array Units (FAUs) and precision active coupling equipment relied upon by traditional CPO architectures, potentially leading to long-term shrinking demand for related midstream components.
At the same time, glass substrate concept stocks bucked the trend and rose sharply. Casingtech surged to hit the daily limit up at one point, DR Laser gained over 9%, Hongxing Development rose over 8%, and Rainbow Display surged over 5%.
Capital is flowing out of CPO and PCB midstream manufacturing segments and shifting towards the glass substrate main theme. The value center of the next-generation AI optical interconnect is undergoing a structural shift, exhibiting a clear "seesaw" market pattern.
So, how does this Glass Bridge, which has triggered a deep market reaction, actually operate? Corning's official technical documentation provides a systematic explanation.
CPO Sector Plummets: The Impact Logic of Glass Bridge
The core reason for the sharp decline in the CPO sector is the potential substitution effect of Glass Bridge on the existing supply chain landscape.
In the traditional Co-packaged Optics (CPO) architecture, the coupling between optical fibers and Photonic Integrated Circuits (PICs) primarily relies on Fiber Array Units (FAUs) and precision active alignment equipment. This stage involves complex processes and high manufacturing costs and represents the core value of 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 optical fibers and PICs, eliminating the need for active alignment equipment.
The market therefore worries that once this solution achieves mass production and adoption in high-density scenarios, the demand for traditional FAUs and lens coupling components will face long-term shrinkage, and the competitive moats of existing midstream CPO manufacturers will be weakened.
How Glass Bridge Operates: Three Core Technical Features
Corning's official documentation positions Glass Bridge as an optical fiber-to-PIC connector platform for next-generation optical architectures, supporting three application scenarios: Near-Package Optics (NPO), Co-packaged Optics (CPO), and high-density photonic modules. Its technical architecture consists of three core features.
Wafer-level manufacturing, supporting production consistency
The core components of Glass Bridge are produced using wafer-level manufacturing processes, utilizing glass ion-exchange (IOX) waveguides to achieve passive alignment. This means the coupling between optical fibers and PICs does not require an active calibration process.
This design reduces manufacturing complexity while supporting consistent optical integration at high volumes, which Corning positions as the key foundation for achieving cost-effective mass production.
Standardized TMT physical contact interface
Glass Bridge employs a standard TMT ferrule to construct a re-pluggable physical contact connection interface, allowing it to integrate more naturally with the existing optical ecosystem while supporting reliable, maintainable connections.
The standardized interface lowers the integration barrier for system designers, indicating that this platform is not a complete disruption of the existing ecosystem but rather an expansion of capabilities based on existing standards.
Detachable high-density connector architecture
Glass Bridge is designed as a detachable connector platform, with a single connector supporting over 24 optical channels and offering customizable pitch configurations to adapt to different system and PIC requirements.
The detachable design provides greater flexibility during assembly, testing, and system integration stages, accommodating the needs for rework and flexible adjustments in the processes for high-density optical systems.
Comparison with Traditional FAU Solutions: Supplement, Not Complete Replacement
In its official FAQ, Corning clearly states the relationship between Glass Bridge and traditional FAU solutions: traditional Fiber Array Units remain widely effective in current applications. However, in scenarios with extremely high fiber counts, their assembly and scaling complexity increases significantly.
Glass Bridge is positioned as a "supplement" to FAU solutions. By providing a wafer-level passive alignment alternative path, it supports higher density, greater scalability, and detachable system integration.
This statement somewhat tempers the market's extreme expectation of a "complete replacement," but it does not change the direction of the technological trend.
As AI data centers' requirements for optical interconnect density continue to rise, the applicability of traditional FAUs in the highest-density scenarios will gradually narrow. Wafer-level solutions represented by Glass Bridge are filling this space.
Value Chain Reshuffling: Capital Shifts from CPO to Glass Substrate
The market's reaction to Glass Bridge has gone beyond the scope of a single technical event, triggering a re-evaluation of the value chain distribution within the AI optical interconnect industry.
Huaxi Securities believes glass substrate is seen as the next-generation core material for advanced packaging, surpassing current silicon interposers and organic substrates. Against the backdrop of surging demand from AI computing chips for high-frequency signals, high integration density, and large-size packaging, as well as domestic manufacturers facing patent blockades for silicon substrates, glass substrate has become a key window for China's advanced packaging industry to achieve differentiated breakthroughs.
Currently, glass substrate and TGV (Through-Glass Via) technologies are at a critical juncture for industrialization breakthroughs. The demand from AI computing power provides ample momentum for industrial adoption.
Capital flows confirm this logic shift: glass substrate concept stocks like Casingtech, DR Laser, Hongxing Development, and Rainbow Display collectively showed strong performance, forming a stark contrast with the CPO sector. Market sentiment is shifting from the manufacturing segments of midstream optical components and modules towards the more upstream specialty materials segment. The industrial value center of the next-generation AI optical interconnect is being reshaped.
This article is from the WeChat public account: Wall Street News , author: Gao Zhimou
