Physics

Dr. Amit Agrawal
National Institute of Standards and Technology Gaithersburg, USA

Abstract:

Over the last decade, flat optical elements composed of an array of deep-subwavelength dielectric or metallic nanostructures of nanoscale thicknesses – referred to as metasurfaces – have revolutionized the field of optics and nanophotonics. Because of their ability to impart an arbitrary phase, polarization or amplitude modulation to an optical wavefront as well as perform multiple optical transformations simultaneously on the incoming light, they promise to replace traditional bulk optics in applications requiring compactness, integration and/or multiplexing. The primary focus of research in this area has been on applications requiring arbitrarily manipulation of light in the spatial domain such as high numerical aperture focusing or generation of novel polarization states and holograms.

In this talk, we demonstrate the versatility of spatial shaping metasurfaces to be directly integrated on integrated nanophotonic chips for their applications as an interface to quantum systems. Through spatial multiplexing of metasurfaces integrated with grating out-couplers directly on a nanophotonic chip, we show the ability to create arbitrary optical fields in the far-field to enable applications such as cold atom traps and atomic clocks. Finally, we conclude by discussing the ability of metasurfaces to fully shape the Spatio-temporal properties of light at the ultrafast time scale, and on nanometer length scales.