Researchers in Japan have demonstrated that single-mode polymer waveguides fabricated on glass-epoxy substrates offer the stability and optical performance necessary for co-packaged optics (CPO) systems using external laser sources (ELS). Published in the IEEE Journal of Lightwave Technology, the study reveals a path to improving data center and AI accelerator interconnects through mechanically flexible, low-loss polymer waveguides.
Led by Dr. Satoshi Suda of Japan’s National Institute of Advanced Industrial Science and Technology, the research team created 11-mm-long polymer waveguides using direct laser writing on FR4 substrates. These waveguides were optimized to match the mode field of standard single-mode fibers and exhibited uniform dimensions, low polarization-dependent loss, and minimal differential group delay—key characteristics for reliable photonic integrated circuit (PIC) performance in high-density environments.
The study also confirmed the waveguides’ resilience under prolonged operation. Tests with an external laser source supplied by Furukawa Electric showed consistent insertion loss, high polarization extinction ratios, and thermal stability over six continuous hours of operation. These results validate polymer waveguides as a scalable, cost-effective component for next-generation CPO systems in data center and AI infrastructure.
• Glass-epoxy-based polymer waveguides optimized for CPO applications
• Fabricated using direct laser writing on FR4 substrates
• Low polarization loss, low group delay, and strong thermal performance
• Validated under extended high-power operation with Furukawa ELS
• Suitable for PIC-ELS coupling in AI and data center interconnects
“These findings demonstrate the strong potential of polymer waveguides for practical deployment in demanding CPO systems, providing a reliable foundation for next-generation high-density and high-capacity optical communication technologies,” said Dr. Satoshi Suda.
