CAREER:Electrically Tunable van der Waals Optical Nanoantennas Photodetectors and Metasurfaces

North Carolina State University, Raleigh NC

Investigators

Abstract

Nontechnical Description: Compact optical devices with incredible capabilities can be created by arranging tiny structures, known as metasurfaces, made from special optical materials at the nanoscale. These metasurface devices find applications across a broad spectrum of photonics. While there have been exciting advancements, metasurfaces are typically static, and their optical behavior is predetermined by the materials used and their initial design. The challenge lies in developing techniques that allow metasurfaces to have an adjustable optical response, a crucial feature for various applications. The research team is taking on this challenge by introducing a novel approach using van der Waals materials to create compact photonic devices and metasurfaces that can be tuned with electrical bias. Through a combination of computational simulations and real-world experiments, the team aims to showcase the ability to dynamically switch and tune the optical properties of these van der Waals devices and metasurfaces in the visible spectral range. This project opens up new possibilities for programmable wavefront manipulation, optical modulation, and sensing for applications both in free space and on-chip. Beyond the research, the team is committed to education and outreach. Their integrated plan involves engaging students from grades 7-12 up to the graduate level. By participating in this project, students get exposure to rapidly evolving fields such as materials science, optics, and nanotechnology, contributing to their educational journey and fostering interest in cutting-edge technologies. Technical Description: Optical metasurfaces consist of ultrathin photonic devices that feature two-dimensional arrays of sub-wavelength nanoantennas, crafted from either plasmonic materials or dielectric materials. This technology has granted unprecedented control over light, unlocking a diverse range of optical applications. Although actively tuning the response of metasurfaces is highly desirable for various applications, it remains a challenging task. This project delves into the utilization of van der Waals materials to create electrically tunable photonic devices and metasurfaces. The research team aims to showcase reversible, non-volatile, multi-state/continuous switching, and spectral tuning of light scattering, reflection, and chiral-optical absorption by adjusting the van der Waals antenna and metasurfaces in the visible spectral range. Additionally, the technology is implemented with chiral van der Waals nanostructures to create a broadband, electrically tunable circularly polarized light photodetector. The principal investigator plans to leverage their existing efforts and successful experience in educating students, particularly those from underrepresented groups, across different levels. This will be achieved through new course development and outreach programs. The outcomes of this project introduce a new class of tunable metasurfaces and photonic devices based on van der Waals materials, offering a wide range of applications, including optical modulation, photodetection, tunable color filtering and displays, and programmable and active wavefront manipulation. 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.