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Search Publications by: Fabrizio Giorgetta (Fed)

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Displaying 76 - 100 of 156

Optical two-way time and frequency transfer over free space

April 28, 2013
Author(s)
Fabrizio R. Giorgetta, William C. Swann, Laura C. Sinclair, Esther Baumann, Ian R. Coddington, Nathan R. Newbury
The transfer of high-quality time-frequency signals between remote locations underpins many applications, including precision navigation and timing, clock-based geodesy, long-baseline interferometry, coherent radar arrays, tests of general relativity and

Absolute spectroscopy of N2O near 4.5 um with a comb-calibrated, frequency-swept quantum cascade laser spectrometer

January 14, 2013
Author(s)
Kevin O. Knabe, Paul A. Williams, Fabrizio R. Giorgetta, Michael Radunsky, Chris Armacost, Sam Crivello, Nathan R. Newbury
We present absolute line center frequencies for 24 fundamental nu-3 ro-vibrational P-branch transitions near 4.5 um in N2O with an absolute frequency uncertainty of 800 kHz. The spectra were acquired with a swept laser spectrometer consisting of an

Broad-band frequency references in the near-infrared: accurate dual comb spectroscopy of methane and acetylene

December 1, 2012
Author(s)
Alexander M. Zolot, Fabrizio R. Giorgetta, Esther Baumann, William C. Swann, Ian R. Coddington, Nathan R. Newbury
The Doppler-limited spectra of methane between 176 THz and 184 THz (5870-6130 cm −1) and acetylene between 193 THz and 199 THz (6430-6630 cm −1) are acquired via comb-tooth resolved dual comb spectroscopy with frequency accuracy traceable to atomic

3D Precision Imaging with a Terahertz-bandwidth, Comb-calibrated Swept Laser

August 26, 2012
Author(s)
Esther Baumann, Fabrizio R. Giorgetta, Ian R. Coddington, Kevin O. Knabe, Laura C. Sinclair, William C. Swann, Nathan R. Newbury
A frequency-comb and MEMS-based external-cavity laser are integrated into a THz-bandwidth LIDAR system. Range to a diffuse target is measured at sub-msec update times, a comb-based precision/accuracy of 100 nm, and a resolution of 150 microns. Example 3D

A method for comparing remote optical clocks over a free-space optical link

July 9, 2012
Author(s)
William C. Swann, Fabrizio R. Giorgetta, Ian R. Coddington, Esther Baumann, Jean-Daniel Deschenes, Laura C. Sinclair, Alexander M. Zolot, Nathan R. Newbury
We demonstrate a method to compare optical clocks approaching 10 -17 uncertainties through the exchange of optical pulses from phase-locked frequency combs. We discuss results over a 120 m air path and prospects for longer distances.

Frequency characterization of a swept and fixed-wavelength external-cavity quantum cascade laser by use of a frequency comb

May 21, 2012
Author(s)
Kevin O. Knabe, Paul A. Williams, Fabrizio R. Giorgetta, Chris Armacost, Michael Radunsky, Nathan R. Newbury
The instantaneous optical frequency of an external-cavity quantum cascade laser (QCL) is characterized by comparison to a near-infrared frequency comb. Fluctuations in the instantaneous optical frequency are analyzed to determine the frequency noise power

Two-Way Link for Time Interval Comparison of Optical Clocks over Free-Space

May 11, 2012
Author(s)
Fabrizio R. Giorgetta, William C. Swann, Ian R. Coddington, Esther Baumann, Jean-Daniel Deschenes, Laura C. Sinclair, Alexander M. Zolot, Nathan R. Newbury
We demonstrate a free-space link for clock comparisons based on the two-way exchange of pulse trains from combs. The residual uncertainty is 5 * 10^17 in 100 seconds over a 120 m air path, with longer distances possible.

Comb-assisted swept laser spectroscopy with a mode-hop free tunable external cavity QCL

May 1, 2012
Author(s)
Kevin O. Knabe, Fabrizio R. Giorgetta, Nathan R. Newbury, Chris Armacost, Michael Radunsky, Sam Crivello, Timothy Day, Paul A. Williams
We demonstrate sub-MHz spectral resolution of N 2O absorption spectra acquired with a swept external-cavity quantum cascade laser (QCL) over 0.87 THz. The QCL frequency is monitored by sum -frequency generation with an optical fiber frequency comb.

Broad bandwidth trace gas and standoff detection with infrared frequency comb sources

March 11, 2012
Author(s)
Nathan R. Newbury, Alexander M. Zolot, Esther Baumann, Fabrizio R. Giorgetta, Florian B. Adler, Ian R. Coddington, Kevin O. Knabe, Lora L. Nugent-Glandorf, Paul A. Williams, Scott A. Diddams, Tyler W. Neely
An optical frequency comb based on the output of a mode-locked femtosecond laser can be used in spectroscopic studies and sensing applications. The broad array of frequency modes simultaneously provides high spectral resolution and broad wavelength

Direct-comb molecular spectroscopy with accurate, resolved comb teeth over 43 THz

February 15, 2012
Author(s)
Alexander M. Zolot, Fabrizio R. Giorgetta, Esther Baumann, Jeffrey W. Nicholson, William C. Swann, Ian R. Coddington, Nathan R. Newbury
We demonstrate a dual comb spectrometer using stabilized frequency combs spanning 176 THz to 219 THz (1370 nm to 1700 nm) in the near infrared. Measurements of amplitude and phase response at each individual comb tooth span the full 43 THz, generating ~430

High-resolution, high-accuracy dual comb spectroscopy with over 40 THz bandwidth

January 20, 2012
Author(s)
Alexander M. Zolot, Fabrizio R. Giorgetta, Esther Baumann, William C. Swann, Jeff Nicholson, Ian R. Coddington, Nathan R. Newbury
Most spectroscopic instruments directly measure optical wavelength, which is converted to frequency and calibrated against spectral features that have traditionally been measured using complicated frequency chain methods. In the past decade optical