Absolute distance measurement using cross correlation interferometer with a repetition rate multiplication frequency comb

Abstract

In this paper, the Fabry-Perot etalon is used to multiply the repetition rate of the fiber optical frequency comb. The repetition rate is amplified from 250 MHz to 10 GHz, and the corresponding pulse interval is reduced from 1200 mm to 30 mm. In terms of the pulse cross correlation ranging method, repetition rate multiplication can greatly reduce the length requirement of the scanning reference arm. We analyze the principle of cross correlation interferometry based on repetition rate multiplication frequency comb in detail. A numerical mode of the function has been comprehensively established. The basic parameters of optical source and Fabry-Perot cavity for the influence of filtered optical spectrum and cross correlation fringe have been analyzed through the numerical simulation. The multiplied frequency comb is utilized for absolute distance measurement with a pulse cross correlation method. We show that in comparison to a conventional counting interferometer an agreement within 4 μm for distances up to 210 mm is found.