Method of big step height measurements based on white light frequency domain interferometry

A novel method based on white light frequency domain interferometry to measure the big step height with high resolution is presented. The measuring range is determined by the central wavelength of the light source and the spectral resolution of the spectrometer, and the maximal range is up to millimeter magnitude. In the verification experiments, the 298.57 m step height was successfully measured with this method, the standard deviation of repeated measurements is less than 0.03 m, the maximal root mean square error is 0.94 m and the experimental results agree well with the actual values.