Quantification of optical gain-limiting processes in silicon nanocrystals using microcavities
Abstract/Contents
- Abstract
- The past two decades have witnessed a dramatic surge in efforts to elicit active optical functionality out of silicon. Active silicon-compatible devices such as all-optical switches, electro-optic modulators, and high-speed photodetectors have been realized across numerous laboratories. A silicon-based, electrically-pumped laser now remains one of the final obstacles toward ushering in the era of chip-scale nanophotonics and optical interconnects. Among various options, light emitting Si-nanocrystals (Si-nc) and Si-nc sensitized erbium have shown received most attention as a silicon-compatible, near-infrared- (600--1000 nm) and telecom-wavelength (1550 nm) gain-media due to demonstrations of optical gain. Ever since the first and the famous report of optical gain in the year 2000, the measurements have been fraught with controversy with numerous laboratories since then having tried and failed to reproduce these observations. Even in the successful experiments, there exists a considerable spread in the reported conditions required for optical gain. Despite the decade that has nearly elapsed since the first gain measurements, the lack of a Si-nc or a Si-nc sensitized erbium laser remains an experimental fact. Rather than inquiring about the conditions leading to optical gain, such a situation demands for taking a step back and investigating the achievability of the gain itself. The present thesis concerns itself with answering this question in two steps. The first step is an identification of the constraints necessary on the material properties for optical gain to be possible. The second step is a ensuring the satisfaction of these constraints by an accurate measurement of the material properties. Following our identification of free-carrier absorption (FCA) as the fundamental gain-limiting mechanism in semiconductors, we develop a microcavity-based spectroscopic technique for its accurate quantification in Si-nc. We build up to the development of this technique in several intermediate steps including Si-nc synthesis, microcavity modeling, fabrication and testing, and modeling of carrier generation/recombination processes in the quantum dots. Finally we extend our FCA measurement to telecom wavelengths (1550 nm) using pump-probe measurement. Besides enabling us to conclude on the possibility of optical gain in Si-nc sensitized erbium, the pump-probe measurements allow for comparison of the new microcavity-based specroscopy against this well-established technique.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Copyright date | 2010 |
| Publication date | 2009, c2010; 2009 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Kekatpure, Rohan Deodatta |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering |
| Primary advisor | Brongersma, Mark L |
| Thesis advisor | Brongersma, Mark L |
| Thesis advisor | Fan, Shanhui, 1972- |
| Thesis advisor | Miller, D. A. B |
| Advisor | Fan, Shanhui, 1972- |
| Advisor | Miller, D. A. B |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Rohan Deodatta Kekatpure. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Ph.D. Stanford University 2010 |
| Location | electronic resource |
Access conditions
- Copyright
- © 2010 by Rohan Deodatta Kekatpure
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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