Metamaterials and metasurfaces exhibit electromagnetic properties different from those of the constitutive materials. By changing the size, shape, and magneto-dielectric properties of the constitutive elements, the effective permittivity and permeability of the metamaterial can be tailored to achieve the optical effect required for a given application. Ultrathin layers of metamaterial, known as metasurfaces, consist of subwavelength-sized dielectric or plasmonic resonators, not necessarily arranged periodically. By exploiting the shape-dependent plasmonic or Mie resonances, metasurfaces can be used to alter the phase, amplitude and/or polarization of light over subwavelength scales. These surfaces enhance the light matter interaction and can enable more efficient photoelectronic devices. In this talk, first I’ll describe the basics of the design and modeling, then discuss an application of very high reflection with no transmission and absorption, and finally walk through a list of applications of my current interest.