High-resolution temperature and acoustic pressure sensors utilizing slow-light fiber Bragg gratings

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Slow-light fiber Bragg gratings (FBGs) have attracted interest because they exhibit extremely narrow resonances (~60 fm) on the edge of their bandgap, leading to low group velocities (~290 km/s) and high Q factors (~30 million) in a ~cm-long device. They are fabricated by writing strong index modulations in the core of a single-mode fiber. They can also be used to make fiber sensors with record sensitivities. This work demonstrates how slow-light FBG sensors have pushed the limit of temperature and pressure sensing by at least one order of magnitude over conventional FBG sensors. Specifically, it reports a slow-light FBG temperature sensor with a resolution as high as 0.3 m°C/√Hz, an excellent stability (2 m°C/minute), and a low absorption losses (0.02 m−1 at 1550 nm) as required for negligible self-heating. These sensors were instrumental in recording for the first time the very small temperature changes induced by anti-Stokes fluorescence in optically pumped single-mode fluorozirconate fibers and measuring small absorptive losses with calorimetry. The work also reports a slow-light FBG microphone with a resolution of ~200 μPa/√Hz (100 Hz--20 kHz) and a slow-light FBG hydrophone with a resolution of ~700 μPa/√Hz (2 kHz--100 kHz). Their performance is about one order of magnitude better than that currently reported for conventional FBG sensors, and within two orders of magnitude of that measured by the more fragile membrane-based fiber sensors. With further improvement, slow-light FBGs could be utilized for high-resolution pressure sensing applications such as in the deep sea, structural monitoring, and seismic research.


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 2019; ©2019
Publication date 2019; 2019
Issuance monographic
Language English


Author Arora, Arushi
Degree supervisor Digonnet, Michel J. F
Thesis advisor Digonnet, Michel J. F
Thesis advisor Kahn, Joseph M
Thesis advisor Solgaard, Olav
Degree committee member Kahn, Joseph M
Degree committee member Solgaard, Olav
Associated with Stanford University, Department of Electrical Engineering.


Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Arushi Arora.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis Ph.D. Stanford University 2019.
Location electronic resource

Access conditions

© 2019 by Arushi Arora
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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