Events at Physics |
Optical metamaterials are man-made materials in which structuring is used to control the effective optical properties. Using the engineering freedom associated with structuring, researchers have utilized metamaterials for a number of exotic applications including sub-diffraction limit imaging and cloaking. However, absorption loss has been a major impediment to the adoption of metamaterials in practical applications. This absorption loss arises due to ohmic damping in the metals that traditionally comprise the unit cell. In this talk, I will discuss all-dielectric metamaterials in which metal, and the accompanying absorption, is completely avoided. As with their metallic counterparts, manipulation of the unit cell structure of all-dielectric metamaterials offers a means to engineer a wide variety of optical properties. Along these lines, I will discuss several implementations of all-dielectric metasurfaces with functionalities that include polarization control, wavefront tailoring, near-unity reflection, and sharp Fano resonances. The freedom to achieve a wide variety of optical properties, combined with the reduction in absorption loss, could lead to ultra-thin optical elements including lenses, waveplates and sensors as well as more complex assemblies of these elements in the form of metaoptics.