A proposed optical frequency synchronization system for the South African MeerKAT radio telescope

摘要

The South African MeerKAT radio telescope, a precursor to the Square Kilometre Array (SKA) will be incorporated into the mid-frequency component of SKA Phase 1. After a decade of planning, designing and construction, the MeerKAT radio antenna was officially inaugurated in July of 2018. Several exciting astronomical phenomena have already been observed with the MeerKAT radio telescope. Images produced from radio waves collected by the telescope revealed a wealth of ground-breaking astronomical wonders. For radio antenna array applications, the image quality is associated to the accuracy and stability of the phase measurements. The MeerKAT radio instrument is no exception to this, as ultra-stable clock signals will be disseminated to remote dishes across optical fibre up to 12 km in length. In this paper, with the purpose of application to MeerKAT, we propose and demonstrate a novel frequency dissemination and synchronisation system using a vertical cavity surface emitting laser (VCSEL) based phase correction actuator together with the inherent chromatic dispersion properties of the fibre. Frequency dissemination stabilities of 4.44 x 10(-12) at 1 s and 4.86 x 10(-14) at 10(4) s were successfully measured across the 26 km G.655 fibre link.