Univ. of Arkansas Professors Awarded $250K NSF Grant for Microwave Photonics Chip

The U.S. National Science Foundation has awarded a $250,000 grant to two professors at the University of Arkansas to develop a new integrated microwave photonics (IMWP) chip.

Titled “EAGER: Sapphire Based Integrated Microwave Photonics,” the two-year project will be headed by Samir El-Ghazaly and Shui-Qing Yu, who will use R-plane sapphire technology to build a platform to meets future demands for improvements in performance and efficiency.

The proposed approach enables the integration of complete sets of microwave and optical components such as light sources, analogue and digital signal processing circuits, light detectors, control circuits, and Silicon on Sapphire (SOS) radio-frequency (RF) circuits all-in-one sapphire platform to achieve high-performance and low-cost mixed-signal optical links.

Sapphire has a lower refractive index with an index difference of 0.3 with silicon nitride. Therefore, it could leverage the mature silicon nitride low-loss waveguide technology to produce similar low-loss waveguide-based passive components by drop-in replacing quartz wafers with sapphire wafers.

For RF applications, the sapphire platform has a potential to obtain much higher dynamic range due to low-loss optical waveguides while the competing silicon photonics platform, combined with an off-chip 1.55-μm laser, suffers from the strong two-photon absorption and therefore has a limited dynamic range. As a transparent substrate, sapphire would enable versatile 3D photonics/electronics integration architecture.

This project aims to study the feasibility of the proposed approach by identifying and investigating key fundamental challenges, then conduct a proof-of-concept study to provide an effective route for overcoming the identified obstacles and, eventually, provide a conclusive recommendation as to whether the proposed research is feasible.

As a fully integrated solution to fundamentally address the most important technical challenge in IMWP, the new platform would find applications in defense systems such as radar signal processing and many civilian applications. The broad wavelength coverage enables on-chip sensing applications and could potentially replace the current silicon-photonics for data communications. The solution could also be used in harsh environments such as space and nuclear applications.