Date

5-13-2025

Document Type

Thesis

Abstract

My thesis begins with an overview of LiDAR (Light Detecting and Ranging) and theory for electromagnetic wave propagation. We establish problems that arise from the use of external beam steering components in LiDAR systems. As a possible solution, we introduce the concept of a metasurface with sub-wavelength dimensions. Grating metasurfaces utilize periodicity to change the phase gradient along a surface. Using a row of posts on a substrate, we can confine light towards one side of a structure, deflecting at angles towards a maximum angle determined by the structure’s geometry. These metasurfaces are small enough to be directly incorporated onto an integrated LiDAR chip for solid-state beam steering. We use the COMSOL® Multiphysics simulation software to find the response of a post and an array of posts. An overview of the Wave Optics module and the steps used to build and run our simulations is covered. The three main qualities desired in a post array are the maximum deflection angle, the transmission percentage, and how well it confines light waves. θ (maximum deflection angle) is calculated using the change in phase response between the smallest and largest posts in an array. T (transmission) is given as an output value after simulating a post array in COMSOL®. Confinement was qualitatively determined by examining the electric field profiles of a completed simulation. Subsequent design improvements showed promising results by maximizing the phase change ∆Φ compared to the total length of the array d. Future work could build upon these results to further improve designs, which can then be corroborated by testing fabricated samples.

Department

Photonics and Optical Engineering

Thesis Committee

Dr. Sara Mueller, Thesis Advisor
Dr. Edward F. Deveney, Committee Member
Dr. Samuel Serna, Committee Member

Download

Included in

Physics Commons

Share

COinS