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Displaying 251 - 275 of 469

Frequency comb spectroscopy with coherent optical sampling

April 20, 2009
Author(s)
Ian R. Coddington, Nathan R. Newbury, William C. Swann
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.

Word-synchronous linear optical sampling of 40 Gb/s QPSK signals

March 20, 2009
Author(s)
Tasshi Dennis, Paul A. Williams, Ian R. Coddington, Nathan R. Newbury
We demonstrate word-synchronous measurements of QPSK format 40 Gb/s PRBS signals using linear optical sampling with a precision time-base, which allows us to average waveforms and distinguish between signal distortion and noise in eye diagrams.

High-performance, vibration-immune, fiber-laser frequency comb

March 1, 2009
Author(s)
Esther Baumann, Fabrizio R. Giorgetta, Jeffrey W. Nicholson, William C. Swann, Ian R. Coddington, Nathan R. Newbury
We demonstrate an environmentally robust optical frequency comb based on a polarization-maintaining, allfiber, figure-eight laser. The comb is phase locked to a cavity-stabilized cw laser by use of an intracavity electro-optic phase modulator yielding 1.6

Coherent measurements with fiber-laser frequency combs

February 2, 2009
Author(s)
Nathan R. Newbury, Ian R. Coddington, Tasshi Dennis, William C. Swann, Paul A. Williams
The coherent and broad spectral output of fiber-laser frequency combs can be exploited for a variety of high-resolution measurements outside of conventional frequency metrology. We will discuss recent measurements in spectroscopy, ranging, and

Low noise frequency comb based on an all-fiber polarization-maintaining figure-8 laser

February 2, 2009
Author(s)
Esther Baumann, Fabrizio R. Giorgetta, Jeffrey W. Nicholson, William C. Swann, Ian R. Coddington, Nathan R. Newbury
We present a frequency comb based on an all-fiber polarization-maintaining figure-8 laser. It is locked to an optical reference through an intracavity high bandwidth electro-optical modulator and has a flat phase noise of -78 dBc/Hz.

Measuring optical waveforms with fiber frequency combs

January 5, 2009
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 optical sampling.

Alpha-Dot or Not: Comparison of Two Single Atom Optical Clocks

October 5, 2008
Author(s)
Till P. Rosenband, David Hume, Chin-Wen Chou, J.C. Koelemeij, A. Brusch, Sarah Bickman, Windell Oskay, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Nathan R. Newbury, William C. Swann, Wayne M. Itano, David J. Wineland, James C. Bergquist
Repeated measurements of the frequency ratio of Hg + and Al + single-atom optical clocks over the course of a year yield a constraint on the possible temporal variation of the fine-structure constant a. The time variation of the measured ratio corresponds

Recent atomic clock comparisions at NIST

October 1, 2008
Author(s)
Luca Lorini, Neil Ashby, Anders Brusch, Scott Diddams, Robert E. Drullinger, Eric Eason, Tara Fortier, Pat Hastings, Thomas P. Heavner, David Hume, Wayne M. Itano, Steven R. Jefferts, Nathan R. Newbury, Tom Parker, Till P. Rosenband, Jason Stalnaker, William C. Swann, David J. Wineland, James C. Bergquist
The record of atomic clock frequency comparisons at NIST over the past half-decade provides one of the tightest constraints of any present-day, temporal variations of the fundamental constants. Notably, the 6-year record of increasingly precise

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