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Search Publications by: Paul A. Williams (Fed)

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Displaying 76 - 100 of 194

High-stability transfer of an optical frequency over long fiber-optic links

August 1, 2008
Author(s)
Paul A. Williams, William C. Swann, Nathan R. Newbury
We present theoretical predictions and experimental measurements for the achievable phase noise, timing jitter, and frequency stability in the coherent transport of an optical frequency over a fiber-optic link. Both technical and fundamental limitations to

Practical performance limits on optical frequency transfer over fiber optic links

May 4, 2008
Author(s)
Paul A. Williams, William C. Swann, Nathan R. Newbury
We present theory and experiment quantifying the limitations to stable transport of optical frequencies over optical fiber. These are fundamental fiber noise, propagation delay, bidirectional propagation and system noise in the measurement interferometers.

Fiber lasers for frequency standards in optical communications

February 24, 2008
Author(s)
Nathan R. Newbury, William C. Swann, Ian R. Coddington, Paul A. Williams
Optical light with millihertz relative frequency stabilities and subfemtosecond timing jitter can be produced from stabilized cw or mode-locked fiber lasers. We will discuss the generation, fiber-optic distribution and some applications of these coherent

Coherent transfer of an optical carrier over 251 km

October 15, 2007
Author(s)
Nathan R. Newbury, Paul A. Williams, William C. Swann
We transfer of an optical frequency over 251 km of optical fiber with a residual instability of 6×10 -19 at 100 s. This instability and the associated timing jitter are limited fundamentally by the noise on the optical fiber and link length. We give a

Coherent fiber-based frequency combs and cw lasers at 1550 nm

August 26, 2007
Author(s)
Nathan R. Newbury, William C. Swann, Ian R. Coddington, Paul A. Williams
Coherent optical sources in the 1550 nm region of the spectrum have a number of applications in frequency metrology, stable frequency transfer, precision spectroscopy and remote sensing. A narrow-linewidth (~ 1 Hz) single-frequency source can be generated

Biophotonic tools in cell and tissue diagnostics

May 1, 2007
Author(s)
Michael Brownstein, Robert A. Hoffman, Richard Levenson, Thomas E. Milner, Marla L. Dowell, Paul A. Williams, Grady S. White, Adolfas Gaigalas, Jeeseong C. Hwang
In order to maintain the rapid advance of biophotonics in the U.S. and to enhance our competitiveness worldwide, key measurement tools must be in place. As a part of a wide-reaching effort to improve the U.S. technology base, the National Institute of

High Sensitivity Measurements of the Scattering Dispersion of Phantoms using Spectral Domain Optical Coherence Tomography

January 26, 2006
Author(s)
Shellee D. Dyer, Tasshi Dennis, Paul A. Williams, Lara Roberson, Shelley M. Etzel, Robert J. Espejo, Thomas Germer, T E. Milner
We demonstrate a novel technique to determine the size of Mie scatterers with high sensitivity. Our technique is based on spectral domain optical coherence tomography measurements of the dispersion that is induced by the scattering process. We use both Mie