comb-referenced laser distance interferometer for industrial nanotechnology - digital laser distance meter

The performance of the prototype laser interferometer the quality of the frequency comb-
Production of photoelectric devices such as flat panel displays and solar cells. This comb-
The reference interferometer uses four different wavelengths at the same time, and can fully evaluate the stability and uncertainty of the measurement, thus achieving absolute distance measurement.
The measurement results show that the stability reaches 3. 4u2009nm for a 3.
8 m from 1 hour.
The average of 0 u2009 s was further reduced to 0.
57 nm at 100 m/s, with a fractional stability of 1. 5u2009×u200910−10.
When measuring the distance in the air, the uncertainty is estimated at level 10-8 because of the inevitable ambiguity in estimating the refractive index, but it can be enhanced to level 10-10 in vacuum.