Measuring the relative synchronization error of frequency counters with sub-μs accuracy via a phase-stabilized fiber link

When comparing independent simultaneous measurements of the same, non-constant frequency, synchronization errors between the frequency counter´s gate time intervals lead to an apparent frequency deviation between the measurements. Here we present a technique that allows for a remote measurement of the counters´ synchronization offset with sub-microsecond accuracy using a phase-stabilized fiber link.