Traceability of laser frequency/wavelength calibration through the frequency comb at Inmetro

Calibration of Displacement Laser Interferometer Systems for Industrial Metrology

“…An even more accurate reference frequency can be obtained using a frequency comb that gives a direct connection to the realization of the second and takes down the uncertainty from the 10 −11 to the 10 −12 level [14]. Although an iodine-stabilized laser is less suitable for using in a displacement laser interferometer directly, it is possible to establish a direct link to a primary standard when operating a laser interferometer [15].…”