Author Affiliations

Connor Fredrick,^1,2,* Andrew J. Metcalf,^1,2 Daniel Hickstein,¹ David Carlson,¹ Wesley Brand,^1,2 Kartik Srinivasan,³ Scott Papp,^1,2 and Scott Diddams^1,2

¹Time and Frequency Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA

²Department of Physics, University of Colorado, 2000 Colorado Avenue, Boulder, CO 80309, USA

³Microsystems and Nanotechnology Division, National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD 20899, USA

^*Corresponding author: connor.fredrick@colorado.edu