High quality factor phase gradient metasurfaces for nonlinear and reconfigurable nanophotonics
Abstract/Contents
- Abstract
- Emerging optical technologies spanning LIDAR to virtual reality will revolutionize the way we interact with the world around us. Key to these technologies will be the ability to generate tunable, reconfigurable, and compact optics that can replace conventional components like glass lenses and mechanically actuated devices. Metasurfaces, two dimensional arrays of subwavelength optical nanoantennas, promise to dramatically scale down device footprints with nanoscale control of optical wavefront's phase, amplitude, and polarization. However, the geometric design methodologies, weak light-matter interactions of most materials, and nanoscale design mean that metasurfaces are challenging to reconfigure. Amplifying their light-matter interaction and nonlinear responses are thus paramount to designing efficiently reconfigurable (re)active nanophotonic platforms. This thesis demonstrates a novel route to reconfigurable and nonlinear metasurfaces utilizing high quality factor (high-Q) resonances. Using Silicon nanobars as our nanoantenna elements, we demonstrate efficient metasurfaces at telecom frequencies. First, we show that guided mode resonances within individual nanoantennas can be exploited to generate high quality factors in arbitrary phase gradients. Next, we fabricate these structures in a silicon on sapphire platform and reveal record Q factors of 2,500 in beamsteering metasurfaces. Next, we discuss routes to apply these high-Q resonances for electro-optic modulation and nonlinear optics. we show that interfacing our high-Q metasurfaces with Lithium Niobate (LNO) enables efficient modulation of diffraction with an applied DC electric field, enabling compact, solid state wavefront manipulation on a chip. In addition, using the resonant field enhancement afforded by these resonant antennas, we are able to reduce the power required for the nonlinear Kerr effect. Using this, we numerically demonstrate efficient nonlinear and nonreciprocal modulation of diffraction with low illumination power. Finally, we consider more exotic optical potentials in metamaterials. Using plasmonic waveguide-based metamaterials with added loss and gain, we construct a Parity-Time symmetric metamaterial whose bandstructure can be dynamically tuned with the amount of loss and gain. By considering nonlinearities that would naturally occur in these materials, we demonstrate broadband and wide-angle nonreciprocity, a potentially enabling technology in tunable nonlinear free-space isolators. Our results show that resonant and nonlinear nanophotonics can be exploited for efficient wavefront generation and modulation, amenable to ultrathin, reconfigurable optical devices.
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 | 2020; ©2020 |
| Publication date | 2020; 2020 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Barton, David Russell III |
|---|---|
| Degree supervisor | Dionne, Jennifer Anne |
| Thesis advisor | Dionne, Jennifer Anne |
| Thesis advisor | Brongersma, Mark L |
| Thesis advisor | Fan, Jonathan Albert |
| Degree committee member | Brongersma, Mark L |
| Degree committee member | Fan, Jonathan Albert |
| Associated with | Stanford University, Department of Materials Science and Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | David Russell Barton. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2020. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2020 by David Russell Barton
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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