Disordered metasurfaces for unidirectional and synergistic imaging in the mid-infrared

We design a large aperture, all-silicon meta-optic doublet for unidirectional imaging at a wavelength of 4 μm. When illuminated by a plane wave in the forward mode, our unidirectional imager generates an intense spot on its optic axis at a predefined focal length. In the reverse mode, the imaging performance is significantly reduced, accompanied by a dramatic reduction in light intensity on the focal plane. We envision our devices to provide new avenues for the development of metamaterial imaging platforms for applications in defense and data security.