Coherent interferometric absolute distance metrology is one of the most interesting techniques for length metrology. Without movement, measurements are made without ambiguity, by using either one or several synthetic wavelengths resulting from the beating of two or more wavelengths (multiple-wavelength interferometry), or a frequency sweep (frequency-sweeping interferometry). Sensors based on the latter are relatively simple devices and can fulfill an important role in dimensional metrology. In addition, their parameterization flexibility allows trade-offs to be performed, either technology-driven or application-related. We present in detail a theoretical model of frequency-sweeping interferometry and its uncertainty budget, discuss different parameterizations, present a method for drift error compensation, and demonstrate and evaluate sensor performance and robustness with a prototype sensor composed of a mode-hop-free frequency-sweep external-cavity diode laser, a high-finesse Fabry-Perot interferometer (to measure accurately the frequency sweep range), homodyne detection, and data processing. Results have shown that the inaccuracy will not exceed 10 (mu)m for distances up to 1 m, at an affordable degree of complexity.
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