Chromatic confocal microscopy by means of continuum light generated through a standard single-mode fibre

In this paper a confocal profilometer using longitudinal chromatic aberration is presented. The system uses a novel polychromatic illumination source generated by means of non-linear effects in a standard single-mode optical fibre. A wavelength–height codification is realized using the chromatic aberration of a Fresnel lens. The height decoding is obtained by the spectral analysis of the detected light, identifying the most intense spectral component coming from the sample. The height sensitivity of the profilometer is variable and it is related to the full width half maximal value (FWHM) of the system's spectral response. From 700 to 938 nm the experimental value of the FWHM changes from 10.78 to 3.9 µm respectively.