The thickness profile of deposits obtained from Lambertian evaporation sources is highlighted concerning its transmission optical functionality, in the case of dielectric materials. Fresnel diffraction is used to characterize the lateral resolution and intensity on the optical axis of an input gaussian laser beam. Functionality similar to logarithmic axicons, with uniform lateral resolution and also uniform on-axis intensity, is theoretically derived. It is also shown for this particular optical structure that the intensity slope along the optical axis can be changed from positive to negative values by only changing the input beam width.