A new techuique for determining surface roughness in real-time by laser speckle

A new method for determining surface roughness in realtime is proposed in this paper,based on the processing of laser interference spackle.The measurement system includes a He-Ne laser source,a double Dove prism,a laser interferometer,a CCD detector and a data processing device.A rough surface is illuminated by two laser beams which are obtained with the Dave prism,interference spackle of the reflective laser beams from the rough surface can be acquired in CCD detector surface.With the data processing device,the surface roughness can be automatically determined.The experimental results show that the method is superior to other methods in measurement accuracy and range.