Absolute distance measurement using optical sampling by sweeping the repetition frequency

We experimentally demonstrate a method for long distance measurement using optical sampling by sweeping the repetition frequency of the frequency comb. The interferograms can be obtained by continuously changing the repetition frequency, and the distances can be determined via the peak position of the interferograms. Compared with the fringe counting interferometer, the experimental results show an agreement within ±3 µm in 75 m range.