Testing Reflective Optical Surfaces With A Non-Contacting Probe

An optical device is described that performs height data acquisition by focusing a white light beam at a sample surface and processing the backscattered light. The principle of the operation is based on longitudinal chromatic aberration of the focusing lens and on spectral analysis of the image irradiance. The surface microtopography is reconstructed after automatic point by point scanning. A personal computer interfaced to the probe controls the operation and produces the roughness parameters. Highlights of the optical approach are presented, main system characteristics are given and examples of performance on selected objects are demonstrated.