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Search Publications by: Laura Sinclair (Fed)

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Displaying 51 - 75 of 90

Synchronization of clocks through 12km of strongly turbulent air over a city

October 11, 2016
Author(s)
Laura C. Sinclair, William C. Swann, Hugo Bergeron, Esther Baumann, Michael A. Cermak, Ian R. Coddington, Jean-Daniel Deschenes, Fabrizio R. Giorgetta, Juan Juarez, Isaac H. Khader, Keith G. Petrillo, Katherine T. Souza, Michael L. Dennis, Nathan R. Newbury
We demonstrate real-time, femtosecond-level clock synchronization across a low-lying, strongly turbulent, 12-km horizontal air path by optical two-way time transfer. For this long horizontal free-space path, the integrated turbulence extends well into the

Tight real-time synchronization of a microwave clock to an optical clock across a turbulent air path

April 15, 2016
Author(s)
Hugo Bergeron, Laura C. Sinclair, William C. Swann, Craig Nelson, Jean-Daniel Deschenes, Esther Baumann, Fabrizio R. Giorgetta, Ian R. Coddington, Nathan R. Newbury
The ability to distribute the precise time and frequency from an optical clock to remote platforms could enable future precise navigation and sensing systems. Here we demonstrate tight, real-time synchronization of a remote microwave clock to a master

Optical system design for femtosecond-level synchronization of clocks

February 13, 2016
Author(s)
Laura C. Sinclair, William C. Swann, Jean-Daniel Deschenes, Hugo Bergeron, Fabrizio R. Giorgetta, Esther Baumann, Michael A. Cermak, Ian R. Coddington, Nathan R. Newbury
Synchronization of optical clocks via optical two-way time-frequency transfer across free-space links can result in time offsets between the two clocks below tens of femtoseconds over many hours. The complex optical system necessary to support such

Femtosecond synchronization of optical clocks over free-space links

December 11, 2015
Author(s)
Jean-Daniel Deschenes, Laura C. Sinclair, Fabrizio R. Giorgetta, William C. Swann, Esther Baumann, Hugo Bergeron, Michael A. Cermak, Nathan R. Newbury
The use of optical clocks/oscillators in future ultra-precise navigation, gravitational sensing, and relativity experiments will require time comparison and synchronization over terrestrial or satellite free-space links. Here we demonstrate full

Broadband phase spectroscopy over turbulent air paths

September 4, 2015
Author(s)
Fabrizio R. Giorgetta, Greg B. Rieker, Esther Baumann, William C. Swann, Laura C. Sinclair, Jonathan Kofler, Ian R. Coddington, Nathan R. Newbury
Broadband atmospheric phase spectra are measured at sub-milliradian uncertainty corresponding to a 10-13 refractive index change, despite strong decoherence from atmospheric turbulence. A phase-sensitive dual-comb spectrometer acquires spectra over 233 cm

A compact optically coherent fiber frequency comb

August 18, 2015
Author(s)
Laura C. Sinclair, Jean-Daniel Deschenes, Lindsay I. Sonderhouse, William C. Swann, Isaac H. Khader, Esther Baumann, Nathan R. Newbury, Ian R. Coddington
We describe design and operation of a robust self-referenced, optically coherent frequency comb. The system robustness is derived from a combination of an optics package based on polarization-maintaining fiber, high signal-to-noise ratio (SNR) detection of

Frequency-Comb-Based Remote Sensing of Greenhouse Gases over Kilometer Air Paths

October 29, 2014
Author(s)
Greg B. Rieker, Fabrizio R. Giorgetta, William C. Swann, Jonathan Kofler, Alexander M. Zolot, Laura C. Sinclair, Esther Baumann, Christopher L. Cromer, G. Petron, Colm Sweeney, P P. Tans, Ian R. Coddington, Nathan R. Newbury
We demonstrate frequency comb tooth-by-tooth measurements of atmospheric gas absorption across a 2-km, turbulent, open-air path through coherent dual-comb spectroscopy. High accuracy, high signal-to-noise transmission spectra are acquired spanning 5990 to

Operation of an optically coherent frequency comb outside the metrology lab

March 13, 2014
Author(s)
Laura C. Sinclair, Ian R. Coddington, William C. Swann, Archita Hati, Kana Iwakuni, Nathan R. Newbury
Frequency combs can support cutting-edge measurements in areas that include optical clocks and oscillators, high-accuracy frequency and time transfer, precision spectroscopy from the UV to THz regimes, high-accuracy LIDAR, precise microwave photonics, and

High-performance free-space photonic links for frequency/time transfer

September 8, 2013
Author(s)
Nathan R. Newbury, Fabrizio R. Giorgetta, William C. Swann, Laura C. Sinclair, Esther Baumann, Ian R. Coddington
We discuss optical two-way time and frequency transfer over air to connect remote optical clocks/oscillators. This method can link remote sites with a residual timing noise of femtoseconds and a residual fractional accuracy below 10^-18.

The impact of turbulence on high accuracy time-frequency transfer across free space

June 26, 2013
Author(s)
Laura C. Sinclair, Fabrizio R. Giorgetta, William C. Swann, Esther Baumann, Ian R. Coddington, Nathan R. Newbury
Atmospheric optical path-length variations are measured across a 2-km optical link through a frequency comb-based system with femtosecond-level precision. Without mitigation, the turbulent piston effect will severely restrict time-frequency transfer from

A comb-calibrated FMCW LADAR for absolute distance measurements

June 15, 2013
Author(s)
Esther Baumann, Fabrizio R. Giorgetta, Ian R. Coddington, Laura C. Sinclair, Kevin O. Knabe, William C. Swann, Nathan R. Newbury
We present a comb calibrated frequency-modulated continuous wave (FMCW) LADAR system for absolute distance measurements to diffuse or specular surfaces. The FMCW LADAR uses a MEMS-based external cavity laser that is swept quasi-sinusoidally over 1 THz at a

Free-space optical time-frequency transfer over 2 km

June 9, 2013
Author(s)
William C. Swann, Fabrizio R. Giorgetta, Laura C. Sinclair, Esther Baumann, Ian R. Coddington, Nathan R. Newbury
Precision free-space time-frequency transfer could advance fields where present microwave-based transfer is inadequate. We demonstrate an optical free-space link with femtosecond timing deviation and residual instability below 10 −18 at 1000 seconds.