Absorption loss was once thought to be one of the primary impediments to the application of metamaterials and metasurfaces at optical frequencies. However, over the past several years researchers have realized that loss can in fact be harnessed for certain applications and completely avoided in applications where transparency of the material is critical. In this talk I will discuss how absorption loss in plasmonic materials can be utilized for nanoscale heating as well as hot electron-based optoelectronic devices.
I will also discuss all-dielectric metasurfaces that utilize silicon meta-atoms. As with their plasmonic counterparts, manipulation of the unit cell structure of all-dielectric metasurfaces offers a means to engineer a wide variety of optical functionalities, however loss can be largely avoided in such materials. Along these lines, I will discuss several implementations of silicon-based metasurfaces with functionalities that include polarization control, wavefront tailoring, near-unity reflection, and sharp Fano resonances.