Dr. Fabrizio Giorgetta (NIST)
Frequency-comb based open-path time and frequency transfer and its application to clock networks

The networking of optical clocks using time and frequency transfer is essential to realize their full potential for, e.g., the redefinition of the second, relativistic geodesy, and fundamental physics tests. I will discuss optical frequency comb based open-path time and frequency transfer, and recent improvements that reduced its detection threshold from 10’s of nW to 100’s of fW. I will present a proof-of-concept measurement across a 300 km long freespace link and a three-node clock network with optical iodine clocks connected across 14.5 km free-space links. I will discuss upcoming measurement campaigns.