Structuring Light in Space and Time with Optical Metasurfaces
Restricted (Penn State Only)
- Author:
- Zhang, Lidan
- Graduate Program:
- Electrical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- October 02, 2024
- Committee Members:
- Zhiwen Liu, Major Field Member
Xingjie Ni, Chair & Dissertation Advisor
Christine Keating, Outside Unit & Field Member
Madhavan Swaminathan, Program Head/Chair
Sawyer Campbell, Major Field Member - Keywords:
- optical metasurface
hyperspectral polarization imaging
large scale metalens
ultrafast imaging
achromatic metalens
Rotational doppler effect
Faraday Rotation Effect - Abstract:
- Metasurfaces have revolutionized the manipulation of light properties such as amplitude, phase, and polarization. Since their emergence in the early 2010s, optical metasurfaces have found many applications from imaging to beam-steering. However, current design and fabrication of metasurfaces still face three challenges: their slow and costly fabrication methods limit their aperture and industrial applicability. Additionally, their functionality is restricted, making one-shot spectral polarization imaging and ultrafast imaging difficult. Metasurfaces primarily rely on spatial structure engineering, limiting adaptability to temporal tuning. This dissertation addresses these three challenges in three sections: 1. Development of Large-Scale Metasurface Lenses: We fabricate an 80mm metalens using deep UV lithography and construct a metalens telescope to capture the lunar surface. We also design a stair-shaped metalens to achieve achromatic performance across 400nm to 700nm for imaging applications. 2. Multidimensional Snapshot Imaging Using Encoding Metasurfaces: We develop chiral metasurfaces combined with deep learning algorithms for single-shot hyperspectral polarization imaging. We also fabricate a spatiotemporal encoding mask to integrate time information into spatial data, enabling snapshot ultrafast imaging with temporal resolution. 3. Metasurface-Based Rotational Doppler Effect and Faraday Rotation Phenomenon: We create a rotating waveplate with THz rotation speed using polarization-twisting beam, demonstrating the Rotation Doppler Effect by measuring the frequency shift of reflected light. By incorporating a mirror, we demonstrate the Faraday Rotation phenomenon. This work advances the structuring of metasurfaces in both spatial and temporal domains, enhancing their functionality and paving the way for their industrial applications.