Lateral and axial resolution and effective depth scanning range in white Light Confocal Microscope are related to the
range of longitudinal chromatic aberration of system. In this article simulation and fabrication of white Light Confocal
Microscope with tunable longitudinal chromatic aberration is discussed. The simulation has been done by Zemax optical
design software. Generation of longitudinal chromatic aberration has been achieved by using two biconvex lenses with
focal length of 30 mm and 40 mm and a 40x microscope objective. The effect of variation of distance between lenses on
longitudinal chromatic aberration was studied. In addition the optical properties of microscope such as axial and lateral
resolution, numerical aperture, effective depth scanning range and total shift of chromatic aberration in optical axis
direction were studied. Using this setup with a broadband source of 480nm to 650nm tunable effective depth scanning
range covering 23μm to 68μm was achieved. As a result tunable axial resolution of 48nm to 159nm was obtained.
Regarding the scale of the sample we could use the optimum resolution.
An instrument to attain surface topography is White Light Confocal Microscope (WLCM).WLCM utilizes a
spectrometer to analyze the scattering wavelength from the surface of a specimen. In this paper we used a CCD and
some image processing techniques instead of spectrometer to determine the scattered wavelength. Both simulation (By
Zemax Optical Design Software) and experiment have been performed. To reach the longitudinal chromatic aberration,
two biconvex lenses with longitudinal chromatic aberration were used in the simulation and the experiment. Also, the
lateral resolution is provided by a 40X microscope objective lens. The white light source of the experiment setup is a
Xenon lamp and the used wavelength ranges from 420 nm to 630 nm. Comparison of the results showed an acceptable
conformity between the simulation and the experiment. Finally, the topography of the surface was achieved.