Achromatic lenses are cemented with two lenses mainly used to reduced values of spherical aberration, coma, and chromatic aberration. Sunday offer positive achromatic lenses and negative achromatic lens with coatings Structure doublet lenses Material Optical glass, UVFS,Germanium, Silicon,CaF2,MgF2,ZnSe ZnS,Sapphire Diameters Available 0.1mm to 600mm D: Customer Design.