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Displaying 126 - 150 of 225

Ratio of the Al + and Hg + Optical Clock Frequencies to 17 Decimal Places

August 25, 2008
Author(s)
Wayne M. Itano, Till P. Rosenband, David Hume, P.O. Schmidt, Chin-Wen Chou, A. Brusch, Luca Lorini, Windell Oskay, Robert E. Drullinger, Sarah Bickman, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, William C. Swann, Nathan R. Newbury, David J. Wineland, James C. Bergquist
Frequency standards (atomic clocks) based on narrow optical transitions in 27Al + and 199Hg + have been developed over the past several years at NIST. These two types of standards are both based on single ions confined in Paul traps, but differ in the

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

Applications of highly coherent femtosecond fiber lasers

July 13, 2008
Author(s)
Nathan R. Newbury, Ian R. Coddington, William C. Swann
Coherent, broadband fiber lasers produce pulse trains with <1 femtosecond relative timing uncertainty and <1 mHz relative frequency uncertainty. These sources can advance many applications including optical frequency metrology, ranging LIDAR, and broadband

Towards a Low-Jitter 10 GHz Pulsed Source with an Optical Frequency Comb Generator

June 9, 2008
Author(s)
Shijun Xiao, Leo W. Hollberg, Nathan R. Newbury, Scott A. Diddams
We demonstrate low residual timing jitter of 10 GHz pulses from a 1.55 m optical frequency comb generator based on a doubly-resonant electro-optic modulator. The comb spectral phase is shown to be linear for each sideband but of different slopes. The

High resolution spectroscopy using fiber-laser frequency combs

June 8, 2008
Author(s)
Ian R. Coddington, William C. Swann, Nathan R. Newbury
The output of a femtosecond fiber laser can be both spectrally broadened and stabilized, thereby providing a broadband coherent source in the near infrared. In the frequency domain, the result is a frequency comb with frequency stabilities at the

Broadband, frequency comb spectroscopy

May 4, 2008
Author(s)
Ian R. Coddington, William C. Swann, Nathan R. Newbury
A stabilized frequency comb provides a broadband array of highly resolved comb lines. Using a multiheterodyne technique, we measure the amplitude and phase of every comb line, allowing for massively parallel, high-resolution spectroscopy.

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.

Frequency ratio of Al + and Hg + single-ion optical clocks; metrology at the 17th decimal place

March 6, 2008
Author(s)
Till P. Rosenband, David Hume, P. O. Schmidt, Chin-Wen Chou, Anders Brusch, Luca Lorini, Windell Oskay, Robert E. Drullinger, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, W Swann, Wayne M. Itano, David J. Wineland, James C. Bergquist
We report the frequency ratio of the two most accurate and stable atomic clocks with a total fractional uncertainty of 5.2 X 10 -17 . This frequency ratio is the best-known physical constant that is not a simple integer. Repeated measurements during the

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, multiheterodyne spectroscopy using stabilized optical frequency combs

January 2, 2008
Author(s)
Ian R. Coddington, William C. Swann, Nathan R. Newbury
The broadband, coherent nature of narrow-linewidth fiber frequency combs is exploited to measure the full complex spectrum of a molecular gas through multiheterodyne spectroscopy. We measure the absorption and phase shift experienced by each of 155 000

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

Narrow linewidth fiber laser frequency combs

October 15, 2007
Author(s)
William C. Swann, Ian R. Coddington, John Mcferran, Nathan R. Newbury
Fiber laser frequency combs can provide a series of optical lines that span the spectrum from 1 to 2 υm. By tightly locking the frequency comb to an optical reference, it is possible for these comb lines to exhibit residual linewidths below 1 Hz and

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

Narrow linewidth 1.5 ym sources and the thermal limit

July 23, 2007
Author(s)
William C. Swann, Nathan R. Newbury
A measured 1 Hz linewidth between a cavity-stabilized, 1535 nm cw fiber laser and the 1535-nm tooth of a stabilized fiber frequency comb is below the thermodynamic limit of the frequency comb.

Low-noise fiber-laser frequency combs

July 19, 2007
Author(s)
Nathan R. Newbury, William C. Swann
We discuss experimental and theoretical aspects of a low-noise fiber-laser frequency comb, including the experimental configuration and the major contributions to the frequency noise and linewidth of the individual comb modes. Intra-cavity noise sources

Lidar with femtosecond fiber-laser frequency combs

July 8, 2007
Author(s)
Nathan R. Newbury, William C. Swann, Ian R. Coddington
Passively mode-locked fiber lasers produce a broad spectrum of light that is also highly phase-coherent. Such sources have clear potential for remote sensing because their broad spectrum permits high range resolution and the coherence permits operation at

Frequency Comparison of Al + and Hg + Optical Standards

June 24, 2007
Author(s)
Till P. Rosenband, David Hume, Anders Brusch, Luca Lorini, P. O. Schmidt, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, W Swann, Windell Oskay, Wayne M. Itano, David J. Wineland, James C. Bergquist
We compare the frequencies of two single ion frequency standards: 27Al + and 199Hg +. Systematic fractional frequency uncertainties of both standards are below 10 -16, and the statistical measurement uncertainty is below 5 x 10 -17. Recent ratio
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