A laser-driven fiber optic gyroscope for inertial navigation of aircraft
Abstract/Contents
- Abstract
- Despite longstanding success as the world's most commercially successful fiber optic sensor, the fiber optic gyroscope (FOG) suffers from relatively poor scale factor stability compared to its competitors in the market for inertial navigation of aircraft. One way to improve the stability is to replace the broadband superfluorescent fiber source (SFS) used to interrogate the FOG with a laser, though this choice reintroduces coherent backscattering, polarization coupling, and other coherent errors into the FOG output. In this thesis we develop a new analytical model of the polarization coupling errors, the first to include the effects of dynamic phase biasing, which is used in essentially all FOGs. We also develop a new model of the backscattering errors which can be used to provide quantitative estimates of the backscattering noise and drift far faster than existing models. Combining these calculations of the backscattering and polarization coupling errors with experimental measurements, we show that navigation-grade noise and drift performance is possible for a laser with a linewidth in the 10's of GHz range. We propose and test several methods of broadening the linewidth of a single mode laser to this level. Ultimately the most successful method uses an electro-optic phase modulator driven by either a pseudo-random bit sequence (PRBS) or a Gaussian white noise (GWN) to scramble the phase of a single mode laser and thereby broaden its linewidth. Using a PRBS-modulated laser as a source for a FOG we demonstrate the first laser-driven FOG with noise below the requirement for inertial navigation of aircraft (0.001 deg/h^1/2). Through calculations and experiments we show that the width and carrier suppression in the modulated laser spectrum can be improved by replacing the PRBS modulation with a GWN modulation. In a FOG driven by a laser with GWN modulation we measure an ARW of 0.00055 deg/h^1/2, a drift of 0.0068 deg/h, and a light source mean wavelength stability below 0.15 ppm. This performance represents the first time that the noise, drift, and scale factor stability requirements for inertial navigation of aircraft are met in a laser-driven FOG. Possibilities for further improvements to a laser-driven FOG are discussed.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Chamoun, Jacob Nemr |
|---|---|
| Associated with | Stanford University, Department of Applied Physics. |
| Primary advisor | Digonnet, Michel J. F |
| Thesis advisor | Digonnet, Michel J. F |
| Thesis advisor | Safavi-Naeini, Amir H |
| Thesis advisor | Solgaard, Olav |
| Advisor | Safavi-Naeini, Amir H |
| Advisor | Solgaard, Olav |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Jacob Nemr Chamoun. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Jacob Nemr Chamoun
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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