Incorporating an Optical Clock into a Time Scale at NIST: Simulations and Preliminary Real-Data Analysis
Jian Yao, Jeffrey Sherman, Tara Fortier, Thomas Parker, Judah Levine, Joshua Savory, Stefania Romisch, William McGrew, Xiaogang Zhang, Daniele Nicolodi, Robert Fasano, Stephan Schaeffer, Kyle Beloy, and Andrew Ludlow Time and Frequency Division, National Institute of Standards and Technology (NIST), Boulder, Colorado, USA
Location: Regency B
Date/Time: Tuesday, Jan. 30, 4:00 p.m.
This paper describes the recent NIST work on incorporating an optical clock into a time scale. We simulate a time scale composed of continuously-operating commercial hydrogen masers and an optical frequency standard that does not operate continuously as a clock. The simulations indicate that to achieve the same performance of a continuously-operating Cs-fountain time scale, it is necessary to run an optical frequency standard 12 min per half a day, or 1 hour per day, or 4 hours per 2.33 day, or 12 hours per week. Following the simulations, a Yb optical clock at NIST was frequently operated during the periods of 2017 March – April and 2017 late October – late December. During this operation, comb-mediated measurements between the Yb clock and a hydrogen maser had durations ranging from a few minutes to a few hours, depending on the experimental arrangements. This paper analyzes these real data preliminarily, and discusses the results. More data are needed to make a more complete assessment.