High-performance Ge/SiGe quantum well waveguide modulators for optical interconnect systems
Abstract/Contents
- Abstract
- Optical interconnects have the potential to help create faster, more powerful computers that use far less energy than they currently do. However, to accomplish this goal, key material and device design breakthroughs must first occur. This Ph.D. dissertation focuses on developing the technology for one component of future optical interconnects, the optical modulator. Ge/SiGe quantum wells exhibit the quantum-confined Stark effect, the strongest high-speed electroabsorption modulation mechanism available in a CMOS-compatible material. We begin by examining the ultrafast carrier dynamics of these quantum wells as a way to understand the fundamental limitations to optical modulators which rely on this material. Using a pump-probe experimental setup, we measured the intervalley scattering time of electrons from the direct valley to the indirect L valley in the conduction band of the germanium wells to be ~185 fs. We also measured field screening in these quantum wells and modeled its recovery through diffusive conduction within 120 ps. This improved understanding of Ge/SiGe quantum wells allowed us to design a waveguide-integrated modulator that relies on selective area growth of this material in thick silicon-on-insulator waveguides. Selective area quantum well waveguide modulators offer the potential of high contrast ratios, low operating energies, and low loss. We developed a novel growth substrate fabrication process to enable high quality selective area growth of Ge/SiGe quantum wells with minimal sidewall growth. We then fabricated selective area modulators integrated with SOI waveguides, and present here preliminary results from these devices.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Claussen, Stephanie Ann |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering |
| Primary advisor | Miller, D. A. B |
| Thesis advisor | Miller, D. A. B |
| Thesis advisor | Harris, J. S. (James Stewart), 1942- |
| Thesis advisor | Saraswat, Krishna |
| Advisor | Harris, J. S. (James Stewart), 1942- |
| Advisor | Saraswat, Krishna |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Stephanie A. Claussen. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Stephanie Ann Claussen
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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