Identification number: LZP-2024/1-0396
Type: Latvian Council of Science Fundamental and Applied Research project
Duration: 01.01.2025-31.12.2027
Project Leader: Dr. Jānis Braunfelds Riga Technical University
Responsible person from Institute of Solid State Physics, University of Latvia (ISSP UL): Dr. Maira Elksne
Project partners: Riga Technical University
Total budget: 300 000 EUR
ISSP UL budget: 144 000 EUR
Project description:
The POLYCONNECT project focuses on integrating optical polymer waveguides into printed circuit boards (PCBs) to create high-capacity optical interconnects for efficient data transmission in data centers. As global data traffic grows exponentially, wavelength division multiplexing (WDM) Silicon Photonics (SiPho) transceivers are increasingly deployed. However, traditional electric interconnects on PCBs cannot meet the scaling demands of energy efficiency, channel density, and bandwidth. To address this limitation, the project aims to replace electric transmission lines with optical waveguides, which offer superior bandwidth-length product and improved data handling capabilities. The ultimate goal of POLYCONNECT is to demonstrate polymer photonic interconnects for high-density data centers, using line card PCB prototypes that enable low power consumption and high-speed multichannel data transmission.
PROJECT PROGRESS:
Work Package 1 has been completed. COMSOL simulations have been developed for the optimization of waveguides and waveguide/optical fiber coupling devices. Suitable waveguide and encapsulation materials for creating data transmission paths on printed circuit boards have also been identified.
Two out of the three tasks in Work Package 2 have been completed. A process for preparing the printed circuit board surface using the encapsulation material has been developed. A fabrication process for SU-8 waveguides has also been developed. The passive alignment process for coupling waveguides to optical fibers has also been initiated.
The first version of a measurement infrastructure for high-speed data transmission has been developed for PAM-4 and OOK formats.
The results achieved have been presented at the Italian Conference on Optics and Photonics (ICOP 2026) in a conference paper entitled “Fabrication and Characterization of Polymer Optical Waveguides on Printed Circuit Boards.”
Two publications presenting the achieved project results have been submitted. One, entitled “Performance and Cross-talk Analysis of Polymer Waveguides for Optical Interconnects,” has been submitted to IEEE Access, while the other, entitled “PolymerWaveguide Optical Printed Circuit Boards for On-Board and Co-Packaged Optics,” has been submitted to IET Optoelectronics.
As part of the project, students are also being trained, and bachelor's and master's theses are being developed.