High-accuracy absolute distance measurement using frequency comb referenced multiwavelength source.

We propose a new approach to multiple-wavelength interferometry, targeted to high bandwidth absolute distance measurement, with nanometer accuracy over long distances. Two cw lasers are stabilized over a wide range of frequency intervals defined by an optical frequency comb, thus offering an unprecedented large choice of synthetic wavelengths. By applying a superheterodyne detection technique, we demonstrated experimentally an accuracy of 8 nm over 800 mm for target velocities up to 50 mm/s.