Surface roughness measurement by digital holography

Surface roughness is crucial guideline to the surface quantity of work piece. This paper demonstrates a simple approach for measurement of surface roughness by using digital holography imaging method based on reflection off-axis lensless Fourier transform (LFT) holography. The surface profiles of the standard roughness sample plates which have the different arithmetic average height values are used as the measurement sample. Comparing the arithmetical average height values of the roughness sample plates obtained from the experiment with the given parameters, the results are in good agreement. It has shown that the method is reasonable and efficient.