Electrically reconfigurable phase-change antennas and metasurfaces
Abstract/Contents
- Abstract
- The success of semiconductor electronics is built on the creation of compact, low-power switching elements that offer routing, logic, and memory functions. The availability of nanoscale optical switches could have a similarly transformative impact on the development of dynamic and programmable metasurfaces, optical neural networks, and quantum information processing. Phase-change materials are uniquely suited to enable the creation of dynamically tunable optical elements and metasurfaces, as they offer high-speed electrical switching between amorphous and crystalline states with notably different optical properties. Their non-volatility also enables metasurface pixels to afford convenient programming of desired functions and a reduced power consumption. The high refractive index of phase change materials has already been harnessed to fashion them into compact optical antennas. Here, we take the next important step, by showing electrically switchable phase-change antennas and metasurfaces that offer strong, reversible, non-volatile, multi-phase switching and spectral tuning of light scattering in the visible and near-infrared spectral ranges. Their successful implementation relies on a careful joint thermal and optical optimization of each optical device that comprises a metal strip that simultaneously serves as a plasmonic resonator and a miniature heating stage. In the dissertation, three functional optical devices are demonstrated with electrical tunability. An optical antenna featuring 30% modulation of the scattered light intensity is first presented and helps us understand our approach of switching phase-change materials. Based on this knowledge, a metasurface is developed, which can afford electrical modulation of the reflectance by more than 4-fold. Lastly, optical antennas are carefully arranged together to build a metasurface that can direct light into different directions and shows promise in individual control of each antenna. The works presented in this dissertation open the opportunity to create a wide range of dynamic random access metasurfaces capable of programmable and active wavefront manipulation.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Wang, Yifei, (Researcher in nanophotonics) |
|---|---|
| Degree supervisor | Brongersma, Mark L |
| Thesis advisor | Brongersma, Mark L |
| Thesis advisor | Fan, Shanhui, 1972- |
| Thesis advisor | Vuckovic, Jelena |
| Degree committee member | Fan, Shanhui, 1972- |
| Degree committee member | Vuckovic, Jelena |
| Associated with | Stanford University, Department of Electrical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Yifei Wang. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/gj432wn5811 |
Access conditions
- Copyright
- © 2021 by Yifei Wang
- License
- This work is licensed under a Creative Commons Attribution Non Commercial Share Alike 3.0 Unported license (CC BY-NC-SA).
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