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Absolute distance measurement has been widely required not only in various industrial fields such as semiconductors, displays, and heavy industry, but also in fundamental and applied research sites. Among the various optical methods for measuring absolute distances, the most widely used method with high precision is multi-wavelength interferometry. In general, multi-wavelength interferometry uses three or more frequency-stabilized lasers to solve the phase ambiguity problem from a large amount of phase information corresponding to several wavelengths. However, despite the high measurement precision of multi-wavelength interferometers, it is practically not easy to install and maintain several frequency-stabilized lasers in terms of cost and maintenance. In this work, we aim to implement a multi-wavelength interferometer using an electro-optic comb with wide spacing between frequency modes. Because the frequency mode spacing of the electro-optic comb is wide enough to be resolved by commercial spectrometers, each frequency mode can be considered as a single frequency-stabilized laser. Through this concept, several frequency-stabilized lasers for multiwavelength interferometer can be replaced with a single electro-optic comb. Absolute distance measurement was performed using the proposed method, and measurement uncertainty evaluation was also performed to evaluate the proposed method. When the electro-optic comb is stabilized by being locked to an atomic clock being traceable to the time standard, so it is expected that it can be easily used to realize length standards or measure ultra-precise absolute distances in the future.
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