RF Interposer, Electronic, and Photonic Co-Design for AI-Scale Co-Packaged Optical Interconnects

Scientific Challenge

Future AI and data-center systems require ultra-high-bandwidth optical interconnects with low power consumption and high integration density. Co-packaged optics (CPO) is a promising solution, but significant challenges remain in integrating photonic devices, wireline electronics, and high-speed interconnects within a compact package. The key challenge is to develop a heterogeneous RF interposer platform that simultaneously provides low insertion loss, minimal crosstalk, precise impedance control, thermal reliability, and cost-effective scalability while supporting both high-speed electrical and optical communication.

Research Objectives

The PhD aims to develop a holistic co-design methodology for next-generation co-packaged optical transceivers by:

• Designing low-loss RF interposer architectures optimized for optical interconnects.
• Co-optimizing passive RF structures, wireline electronics, and photonic components to minimize signal degradation and power consumption.
• Evaluating two integration approaches:
• Fully integrated EIC architecture, where active and passive functions are implemented on-chip.
• Hybrid RF interposer architecture, where active circuits remain on-chip while passive components and impedance matching networks are implemented in the package.
• Quantifying the trade-offs in performance, area, power efficiency, manufacturability, and cost between both approaches.
• Demonstrating a prototype co-packaged optical transceiver system on an RF interposer platform.

Methodology

The research combines:

• Electromagnetic (EM) and multi-physics simulation.
• Passive RF component design and optimization.
• Photonic-electronic circuit co-design.
• System-level modeling and co-optimization.
• Technology benchmarking and trade-off analysis.
• Fabrication and assembly of demonstrator systems.
• Experimental validation through high-frequency electrical, optical, thermal, and reliability measurements.

Demonstrators and Validation

The project will develop and experimentally validate high-speed optical transceiver demonstrators representative of future AI and hyperscale data center applications. The demonstrators will benchmark the performance of fully integrated and hybrid RF interposer-based implementations.

Expected Impact

The outcome will be a validated co-design framework and RF interposer technology platform enabling energy-efficient Tb/s optical interconnects. The research will provide design guidelines for future co-packaged optics systems while reducing silicon area, lowering power consumption, improving scalability, and accelerating deployment of AI and data-center optical connectivity solutions.

Keywords: Co-Packaged Optics (CPO), RF Interposer, Silicon Photonics, Wireline Transceivers, Heterogeneous Integration, AI Infrastructure, Data Centers, High-Speed Interconnects, Electronic-Photonic Co-Design