Fiber-based multiple-access frequency synchronization via 1f–2f dissemination**Project supported by the National Key Scientific Instrument and Equipment Development Project of China (Grant No. 2013YQ09094303).

Abstract

Considering the reference frequency dissemination requirements of the Square Kilometre Array telescope (SKA) project, on the basis of the 1f–2f precision frequency synchronization scheme, we propose and demonstrate a fiber-based multiple-access frequency synchronization scheme. The dissemination reference frequency can be recovered at arbitrary nodes along the entire fiber link. It can be applied to antennas close proximity to the SKA central station, and will lead to a better SKA frequency synchronization network. As a performance test, we recover the disseminated 100-MHz reference frequency at an arbitrary node chosen as being 5 km away from the transmitting site. Relative frequency stabilities of 2.0×10−14/s and 1.6×10−16/104s are obtained. We also experimentally verify the feasibility of a frequency dissemination link with three access points.