Global AI Trend Tracker: AI Expert Call #70: Glass bridge and advanced packaging Quick Note

Research evidence excerpt

Global AI Trend Tracker: AI Expert Call #70: Glass bridge and advanced packaging Quick Note

Global Markets Research

21 July 2026Global AI Trend Tracker

EQUITY: TECHNOLOGY

AI Expert Call #70: Glass bridge and advanced packaging Research Analysts

China Technology

Bing Duan - NIHKQuick Note bing.duan1@nomura.com

+852 2252 2141We hosted AI Expert Call #70 on 21 July, featuring an expert in advanced packaging for

optical-electrical solutions. The expert discussed technical principles and core bottlenecks

of the glass bridge solution; the impact of glass bridges on fiber array unit (FAU); edge

coupling vs surface grating coupling; glass carrier vs ABF glass substrates; as well as

NPO (near field packaging optics) vs CPO (co-packaged optics) and 2.5D packaging. The

following are our key takeaways from the call:

Technical principles and core bottlenecks of the glass bridge solution

• Glass has good light transmittance for both visible and near-infrared light, especially

near-infrared light, which is suitable for optical communication. Glass bridge is used to

connect the optical chip or PIC (Photonic IC) with optical fiber, which have different

mode fields. The core function is to adjust the chip's mode field to a level that matches

the fiber optic mode field through the bridge.

• There are two ways to manufacture glass bridges. One is through ion exchange

(sodium, silver ions), which confines light within the waveguide. This technology is

relatively mature and has already been developed years ago. The second method is

to use laser modification, with less efficiency and higher light loss.

• Corning (GLW US, Not rated) glass bridges use ion exchange technology.

• Current technical challenges for glass bridges include loss control, process stability