CIF:Small:Angular Encoded Imaging

The diffraction limit, a physical phenomenon caused by the wave nature of light, fundamentally constrains the highest resolution of imaging systems, including cameras, microscopes, and telescopes. Surpassing the diffraction limit is accordingly one of the most consequential problems faced by imaging systems today, and doing so could impact every aspect of our lives, from science to medicine, and from engineering to national security. This project will explore a new potential solution to overcome the diffraction limit using a novel optical element, metasurfaces, in conjunction with engineered data-processing computation. A metasurface is a flat, thin glass substrate coated with nanoscale transparent structures that bend the light that travels through them in specially designed ways, and preliminary studies suggest the possibility of using a metasurface along with jointly designed data-processing computation to achieve resolution higher than the diffraction limit. The project will carry out a comprehensive study of the proposed imaging solution from both the theoretical and experimental perspectives. It is anticipated that the project will provide a breakthrough in improving the resolution of imaging systems without needing a rigorously controlled environment, immediately opening the door to a broad range of scientific-imaging applications for disease studies, vaccine development, cancer diagnosis, cell discoveries, material manufacturing, and national security. The computational-imaging knowledge developed during this project will be integrated into K-12, undergraduate, and graduate courses. This project aims to develop a passive imaging solution, angular encoded imaging, that can overcome the diffraction limit without manipulating the illumination of the scene. Angular encoded imaging modulates the environmental light of every incident angle with a unique point-spread function such that the resulting imaging process is mathematically equivalent to a passive band shifting that shifts the high spatial-frequency components of the environmental signal to within the measurable spatial-frequency band controlled by the diffraction limit. Preliminary results show that passive band shifting is possible using metasurface technology, enabling wavelength-scale engineerable optical modulation. This project will establish the theoretical and computational foundations of angular encoded imaging as well as design and build the first angular-encoded-imaging prototype to demonstrate passive sub-diffraction-limit imaging. 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.