Lin Deng’s PhD Proposal Review

“On-chip and multiplexed metasurfaces for light manipulation”

Abstract:

Metasurfaces, which consist of two-dimensional subwavelength nanostructures that can locally manipulate the proprieties of light including amplitude, phase, and polarization, provide an unprecedented means to control optical waves in a prescribed manner. Different functionalities, such as structured light, holograms, and flat lenses, have been realized by metasurfaces. It is a pressing need to develop on-chip and multiplexed metasurfaces to further advance the practical applications of metasurfaces.

In this proposal review, I will discuss two metasurfaces designed with compact size and the ability to multiplex various information channels. The first one can realize mode conversion and wavefront shaping by integrating a C-shape metallic metasurface on top of a planar waveguide. By controlling the orientation of each C-shape nanoantenna, we can achieve mode conversion and focusing effect for the cross-polarized electric fields inside the waveguide. We demonstrated the design and simulation results of 16 scenarios of wideband transverse magnetic (TM) to transverse electric (TE) modes conversion with mode purity up to 98% as well as on-chip lenses at the wavelength of 1550 nm. The second device is to realize the precise control of the amplitude and phase at multiple channels in response to different incident angles and output polarization states by a single planar metasurface. With the help of the genetic algorithm, we designed and demonstrated all-dielectric metasurfaces composed of silicon nano-blocks that can produce multiple complex structured light beams when taking the angle of incidence and the polarization states into consideration. Our research is expected to substantially benefit the development of mode division multiplexing (MDM) as well as polarization-division multiplexing (PDM).

Committee:
Prof. Yongmin Liu (Advisor)