Collaborative Research: 2D ferroelectric nonlinear metasurface holograms

Holography has become a promising approach for image recording and reconstruction with a wide range of applications in many fields such as optical communication, data storage, information security, medical diagnosis, and color displays. Metasurfaces have been widely used to realize ultracompact and efficient nonlinear optical holograms for the generation of complex optical beams and holographic images. However, the existing nonlinear metasurface holograms suffer from several issues such as low conversion efficiency, high absorption loss, and large thickness, which greatly hinder their practical uses in integrated optical devices. In this project, a new type of switchable nonlinear metasurface holograms based on 2D materials will be demonstrated with high conversion efficiency but only nanometer thickness. This research will benefit many promising photonic applications in optical data memory and logic, optical computing, quantum information processing, and flat optoelectronic devices. This project also includes educational activities for training and mentoring graduate and undergraduate students, recruiting underrepresented and female students, and participating outreach activities for high school students. Metasurfaces have been utilized to realize nonlinear holograms for coherent generation of optical beams and holographic images at new frequencies. However, the existing nonlinear plasmonic metasurface holograms suffer from low conversion efficiency and high absorption loss, while the dielectric metasurfaces have the thickness limited to several hundreds of nanometers. The goal of this project is to explore a new type of atomically thin 2D ferroelectric nonlinear metasurface holograms with both amplitude and phase modulations for achieving reconfigurable functionalities in optical beam generation and holographic image reconstruction with high conversion efficiency. In this project, the design, sample fabrication, and experimental characterization of 2D ferroelectric holograms will be conducted to demonstrate the production of nonlinear optical beams and the reconstruction of complex holographic images. Several unique types of 2D ferroelectric materials are utilized to construct the metasurface holograms with distinguished switching functionalities in nonlinear responses. This project will reveal the underlying physics of switchable light-matter interactions at the atomic scale between structured light and 2D materials. 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.