Monitoring of Roughness Profile of Metal Surface Using Diffuse Reflection of Laser Light

This report is concerned with basic research for in-process monitoring of surface profile using diffuse reflection of laser light. The experiment for surfaces machined by an electrical discharge method is conducted. The dependence of diffuse intensity of a reflected laser light on the surface profile is studied by comparing it with rms roughness that is derived from spatial filtering of surface profile measured with a stylus method. The experimental results show that the diffuse intensity is approximately proportional to the rms roughness of a certain filterd surface profile. The theoretical investigation for these results is also presented.