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Physics

Time & frequency

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Displaying 101 - 125 of 272

Broadband Resonator-Waveguide Coupling for Efficient Extraction of Octave Spanning Microcombs

October 1, 2019
Author(s)
Gregory Moille, Qing Li, Travis Briles, Su P. Yu, Tara E. Drake, Xiyuan Lu, Ashutosh Rao, Daron Westly, Scott Papp, Kartik Srinivasan
Frequency combs spanning over an octave have been successfully demonstrated on-chip in Kerr nonlinear microresonators, thanks to their large effective nonlinearity and ability to support a suitable dispersion profile. Efficient extraction of intracavity

pyLLE: a Fast and User Friendly Lugiato-Lefever Equation Solver

May 24, 2019
Author(s)
Gregory T. Moille, Qing Li, Xiyuan Lu, Kartik Srinivasan
The Lugiato-Lefever Equation (LLE), first developed to provide a description of spatial dissipative structures in optical systems, has recently made a significant impact in the integrated photonics community, where it has been adopted to help understand

Femtosecond Time Synchronization of Optical Clocks Off a Flying Quadcopter

April 18, 2019
Author(s)
Hugo Bergeron, Laura C. Sinclair, William C. Swann, Isaac H. Khader, Kevin C. Cossel, Michael A. Cermak, Jean-Daniel Deschenes, Nathan R. Newbury
Optical clock networks promise advances in global navigation, time distribution, coherent sensing, relativity experiments, dark matter searches and other areas1-12. Such networks will need to compare and synchronize clocks over free-space optical links

Tuning Kerr-Soliton Frequency Combs to Atomic Resonances

April 5, 2019
Author(s)
Su P. Yu, Travis Briles, Gregory Moille, Xiyuan Lu, Scott Diddams, Kartik Srinivasan, Scott Papp
Frequency combs based on nonlinear optical phenomena in integrated photonics are a versatile light source that can explore new applications, including frequency metrology, optical communications, and sensing. We demonstrate robust frequency-control

Femtosecond Optical Two-Way Time-Frequency Transfer in the Presence of Motion

February 22, 2019
Author(s)
Laura C. Sinclair, Hugo Bergeron, William C. Swann, Isaac H. Khader, Kevin C. Cossel, Michael A. Cermak, Nathan R. Newbury, Jean-Daniel Deschenes
Platform motion poses significant challenges to high-precision optical time and frequency transfer. We give a detailed description of these challenges and their solutions in comb-based optical two-way time and frequency transfer (O-TWTFT). Specifically, we

Time Synchronization over a Free-Space Optical Communication Channel

December 20, 2018
Author(s)
Isaac H. Khader, Laura C. Sinclair, William C. Swann, Hugo Bergeron, Nathan R. Newbury, Jean-Daniel Deschenes
Free space optical (FSO) communication channels are typically used to transmit high-speed data between sites over the air. Here we repurpose an FSO digital communication system and use it directly for two-way time transfer. We demonstrate real-time

Identifying spurious modes in RF-MEMS resonators using photoelastic imaging

January 21, 2018
Author(s)
Vikrant J. Gokhale, Jason J. Gorman
This paper reports the first use of dynamic photoelastic imaging for identifying in-plane vibration modes in high-frequency MEMS resonators. In a set of width-extensional mode resonators (WE-BARs), we map fundamental width-extensional modes and unwanted

Parametric resonance in linear microresonators using analog feedback

January 21, 2018
Author(s)
Jason J. Gorman, Vikrant J. Gokhale
This paper reports on the design and implementation of an analog feedback controller for generating parametric resonance in linear microresonators that do not intrinsically demonstrate this phenomenon. It is shown that the controller produces a fundamental

Fully-Stabilized All Polarization-Maintaining Fiber Erbium Frequency Comb

May 3, 2017
Author(s)
Laura C. Sinclair, Ian R. Coddington, William C. Swann, Kana Iwakuni, Nathan R. Newbury
We demonstrate a completely polarization-maintaining fiber frequency comb operating at a 200 MHz repetition rate and show stability and noise performance consistent with precision measurement applications. This design is compatible with a robust, fieldable

Time and frequency from electrical power lines

March 6, 2017
Author(s)
Jonathan E. Hardis, Demetrios Matsakis, Blair Fonville
Due to the efforts of Henry Warren, inventor of the Telechron electric clock, electric power companies have been a source of time and frequency reference for the public for over a hundred years. However, advances in technology and changes in the electric

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