DMREF: Magneto-electro-optically coupled hybrid metamaterial thin film platform for photonic integrated circuits

Non-technical Description: Unlike electronic circuits, photonic integrated circuits (PICs) use photons (small, discrete packets of light), rather than electrons, to transmit and process information. While photons provide higher transmission speeds and information capacity, achieving directed signal transmission, optical isolation, and switching remain critical challenges with current weakly-nonlinear materials.

Despite silicon providing an established platform for low-cost, high-volume manufacturing, integrating many dissimilar materials on top poses significant processing and materials compatibility challenges. This Designing Materials to Revolutionize and Engineer our Future (DMREF) award supports research to develop a class of novel hybrid materials (consisting of two constituents at the nanoscale), which will ultimately form several key building blocks for universal, large-scale PICs.

These new hybrid materials provide tailorable optical properties, well-coupled functionalities, easy integration at the device level, and compatibility with semiconductor manufacturing. The scope of the work provides the foundation for a PIC platform that can be manufactured at scale, actualizing the benefits of photon-based circuits, which include: higher speed, lower temperature sensitivity, large integration capacity, and lower costs and carbon footprint, compared to typical integrated circuit (IC) devices.

These advances will provide vital new capabilities in telecommunications, healthcare, sensing, etc., to address critical needs in the Creating Helpful Incentives to Produce Semiconductors (CHIPS) and Science Act through highly efficient device concepts and manufacturing approaches. Furthermore, the research findings will be incorporated into student research training at both graduate and undergraduate levels and education modules for a co-developed course and summer research programs for high school teachers and students.

Technical Description: The scientific goal of the DMREF project is to advance understanding of electro-optical and magneto-optical coupling effects in complex nanoscale hybrid metamaterials with a two-phase hybrid thin film platform to harness the coupling mechanisms between charges, spins, and photons. The technological goal is to demonstrate several key building blocks for future large-scale PICs, including highly efficient and integrated optical switches, nonreciprocal devices, and magneto-optic sensors for PICs, as a proof of concept for this new hetero-integration paradigm.

Specifically, the project will develop a novel hybrid thin film platform with alloyed nanopillars in a dielectric (e.g., BaTiO3) matrix that simultaneously exhibits a magneto-optic effect, an electro-optic effect, and a plasmonic effect, potentially offering the versatility in achieving optical switching and one-way transmission enhanced by plasmonic effects. Echoing the Materials Genome Initiative’s call for “integrating experiment, computation, and theory,” the project creates an effective feedback loop platform by combining experimental efforts (hybrid materials growth, optical property characterization, and device integration and demonstration), theory and modeling (CALculation of PHAse Diagrams (CALPHAD) + phase field modeling (PFM) and mesoscale electromagnetic modeling), and expedited materials prediction and model properties estimation to accelerate the hybrid metamaterial design process.

Major research tasks include: (1) to explore alloyed metallic phase designs for enhanced magneto-optical coupling in metal-oxide hybrid systems and measure on-chip coupling properties; (2) to implement strain engineering for enhanced electro-optical coupling in oxide-based hybrid systems and demonstrate on-chip modulation and device trimming; and (3) to characterize and integrate hybrid systems to form optical devices for potential optical isolation, switching and sensing.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.