Innovations in all-optical image processing: the promise of meta-optics

Nanophotonic devices have gained attention as promising solutions for all-optical image processing. These filters are of subwavelength size and carry potential to address limitations of current image processing technology including processing speed, energy requirements as well as size. We present results demonstrating the use of thin-film absorbers and metasurfaces to real-time detection of edges in images and the visualisation of phase objects including human cancer cells. We discuss the extension of these approaches to implement tuneable devices using phase-change materials and graphene. These approaches have potential for integration into ultra-compact mobile medical diagnostic tools, as well as remote sensing systems.