Surface roughness determination using coherent light - involves comparing specular reflection with light diffused by surface

摘要

Device determines the roughness parameters of an object by comparison of the light reflected specularly by object when it receives a monochromatic, coherent incident ray with the light diffused by the same object, illuminated in the same manner. It has a head which enables the angle of incidence onto the object to be varied linearly, this head comprising a translational system, e.g. a micrometer screw. Light from a laser (1) is polarised (2), modulated (3) and then made to strike the object (6) at an angle (0) via a mirror (4) and a prism (5). A prism (7) and a mirror (4') - identical to their counterparts (5, 4), return the light into the objective (8).