CHROMATIC CONFOCAL PROFILOMETER

A non-contacting optical profilometer, based on the principle of focus multiplexing by w avelength encoding due to a phase Fresnel lens, is presented. The system uses a novel polychromatic illumination source generated by a nonlineal effect in a standard single mode optical fiber. The spectral analysis of the detected light gives the height decoding, by identifying the most intense spectral component coming from the sample. The height sensitivity of the profilometer is related to the width of the spectral response, which depends on the resolving power of the dispersive element and the detection system.