CAREER: Scalable Integrated Nanophotonics with Subwavelength Gratings

Texas Tech University, Lubbock TX

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Photonic integrated circuits (PICs), the counterpart of traditional electronic integrated circuits that use photons instead of electrons for computing or signal processing, have innovated a wide range of optical applications, including quantum processing, biochemical sensing, and light detection and ranging (LiDAR). As electronic integrated circuits have been advanced by increasing the chip integration density, dense-PIC is extremely important. It adds more building blocks for more functionalities, improves modular power efficiency, and decreases unit costs. However, unlike electronics, increasing the photonic chip density is extremely difficult due to the wave nature of light. When two photonic components are close together, large optical crosstalk emerges, introducing noise in the system. This project will explore various subwavelength grating (SWG) metamaterials to push the boundaries of photonic integration density. SWGs have engineering capabilities for index contrast and anisotropic nature, and various next-generation SWG schemes will be investigated for reducing optical crosstalk. Diverse SWG photonic components, including in-plane metalens, will also be developed, and they will be integrated together to hybridize photonic and microfluidic systems. This project will also develop a rich hands-on laboratory course on Integrated Nanophotonics, allowing the students to develop their own photonic chips. Students will explore their ideas of using SWGs for advancing photonic components, integrating research and educational goals of this project. The outcomes of this project will be disseminated to local K-12 students and parents, stimulating the local community’s interest in photonics and nanotechnology. This project proposes to push the limits of scaling issues in integrated nanophotonics, i.e., chip integration density and extreme modal conversion, by exploring the fundamentals of subwavelength gratings (SWGs) and innovating PIC components and chip architecture. The SWGs form effectively anisotropic metamaterials, and their anisotropic properties will be engineered via next-generation SWGs with different directions, angles, and filling fractions. Fundamentals of these SWGs will help increase the overall chip density and advance various PIC components. Different types of in-plane SWG metalenses will also be developed, manipulating the amplitude and phase of the generated beams and achieving diverse beam conversions at sub-mm scale. Such an in-plane metalens system will be co-integrated with a microfluidic chip, realizing a highly stable and efficient on-chip optofluidic system targeting species at hundreds of micron-scale. The proposed research will be integrated with educational and outreach activities via the newly developed hands-on experimental course on Integrated Nanophotonics, helping students in West Texas and increasing the community’s interest in science and technology. 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.