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Displaying 76 - 100 of 216

Absolute frequency measurement of the neutral 40 Ca optical frequency standard at 657 nm based on microkelvin atoms

March 14, 2007
Author(s)
G Wilpers, Christopher W. Oates, Scott A. Diddams, A Bartels, Tara M. Fortier, Windell Oskay, James C. Bergquist, Steven R. Jefferts, Thomas P. Heavner, Thomas E. Parker, Leo W. Hollberg
We report an absolute frequency measurement of the optical clock transition at 657 nm in 40Ca with a relative uncertainty of 7.5x10 -15, the most accurate frequency measurement of a neutral atom optical transition to date. Relative instabilities of 2x10

Frequency Uncertainty for Optically Referenced Femtosecond Laser Frequency Combs

February 1, 2007
Author(s)
Long-Sheng Ma, Zhiyi Bi, A Bartels, Kyoungsik Kim, Lennart Robertsson, Massimo Zucco, Robert Windeler, G Wilpers, Christopher W. Oates, Leo W. Hollberg, Scott Diddams
We present measurements and analysis of the currently known residual frequency uncertainty of femtosecond laser frequency combs (FLFCs) based on Kerr-lens mode-locked Ti:sapphire lasers. Broadband frequency combs generated directly from the laser

Kilohertz-level spectroscopy of cold atoms with a femtosecond optical frequency comb

October 19, 2006
Author(s)
Tara Fortier, Yann Le Coq, Jason Stalnaker, Davi Ortega, Scott Diddams, Christopher W. Oates, Leo W. Hollberg
We have performed sub-Doppler spectroscopy on the narrow intercombination line of cold calcium atoms using the amplified output of a femtosecond laser frequency comb. Injection locking of a 657-nm diode laser with a femtosecond comb allowed for two regimes

Stability measurements of the Ca and Yb Optical Frequency Standards

June 5, 2006
Author(s)
Christopher W. Oates, C Hoyt, Yann Le Coq, Zeb Barber, Tara M. Fortier, Jason Stalnaker, Scott A. Diddams, Leo W. Hollberg
In this paper we describe two types of optical atomic clocks. The first is based on freely expanding calcium atoms and is optimized for experimental simplicity and high stability. The second is based on Yb atoms confined to an optical lattice that is

A Compact High Stability Optical Clock Based on Laser-Cooled Ca

March 27, 2006
Author(s)
Christopher W. Oates, Yann LeCoq, G Wilpers, Leo W. Hollberg
We report new measurements and modifications for a simple, compact, Ca atomic clock at 657 nm. External measurements were made against an independent Yb lattice optical clock via a fs-laser frequency comb. These results lead to upper limits of the Ca clock

Spectroscopy of neutral 174 Yb in a one-dimensional optical lattice

March 27, 2006
Author(s)
C Hoyt, Zeb Barber, Christopher W. Oates, A. V. Taichenachev, V. I. Yudin, Leo W. Hollberg
We report spectroscopy of the 1S 0 - 3P 0 clock transition in neutral 174Yb atoms confined to a one- dimensional optical lattice at the ac Stark shift-canceling wavelength of 759.35 nm. Spectroscopic linewidths as narrow as 4 Hz, full width at half-maximum

Magnetic field-induced spectroscopy of strongly forbidden optical transitions

March 3, 2006
Author(s)
Alexey Taychenachev, V Yudin, Christopher W. Oates, C Hoyt, Zeb Barber, Leo W. Hollberg
We propose a method that uses a static magnetic field to enable direct optical excitation of forbidden electric dipole transitions that are otherwise prohibitively weak. The method is based on mixing of atomic states by a static magnetic field. The method