NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Emily Caldwell, Laura Sinclair, William C. Swann, Nathan R. Newbury, Benjamin Stuhl, Jean-Daniel Deschenes
Abstract
We present a novel frequency comb-based system for optical two-way time-frequency transfer to support very long distance free-space links between clocks. Our Photon-Efficient Agile Comb Optical Clock Synchronization (PEACOCS) system supports sub-femtosecond oscillator synchronization with up to 90 dB of link loss equating to few picowatt levels of received power. Such low power operation is a promising step towards terrestrial links in the 100s of kilometers as well as ground-to-satellite links.
Proceedings Title
2022 Joint conference of the European Frequency and Time Forum & the IEEE International Frequency Control Symposium
Caldwell, E.
, Sinclair, L.
, Swann, W.
, Newbury, N.
, Stuhl, B.
and Deschenes, J.
(2022),
Photon Efficient Optical Time Transfer, 2022 Joint conference of the European Frequency and Time Forum & the IEEE International Frequency Control Symposium, Paris, FR, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933903
(Accessed October 7, 2025)