CHROMATIC CONFOCAL TECHNIQUE

Profilometer Instruments | Lab Services | Application Notes

The Chromatic Confocal technique uses a white light source (LED) that passes through a series of lenses, called an optical pen, which has a high degree of chromatic aberration. The refractive index of the lenses will vary the focal distance of each wavelength of the white light. In effect, each separate wavelength of the white light will focus at a different distance from the optical pen, creating the measurement range. When a surface of interest is within the measurement range a single wavelength of the white light will be in focus while all others will be out of focus. The white light is then reflected back through the optical pen, then through a pin hole filter that allows only the focused wavelength to pass through to a CCD spectrometer. The CCD will indicate the wavelength in focus, which corresponds to a specific distance for a single point. The physical wavelength measured uses no algorithms providing the highest accuracy independent of form, roughness level, illumination and measurement speed. There is no special leveling procedure required. And while others make claims of  resolutions Nanovea provides high accuracy.