In the past few decades, the advancements in nanotechnology have significantly altered many fields of science and technology, especially electronics and integrated photonics. Free-space optics, on the other hand has remained mostly unaffected and even today, "optics" reminds us of carefully shaped and polished pieces of various types of glasses and crystals lumped intosystems.
In this talk I will introduce metasurfaces, a new generation of compact optical elements enabled by the advances in nanotechnology. I will then present some of my work on designing and utilizing metasurfaces with capabilities beyond those of conventional refractive and diffractive optics along two general themes of new concepts and new platforms. More specifically, I will discuss their unprecedented capabilities in controlling light based on its degrees of freedom like illumination angle and polarization. I will then introduce various novel metasurface platforms of conformal and tunable metasurfaces, 3D metasurface beam shapers, and integrated metasurface systems.