ABSTRACT
In this chapter, the particular manufacturing steps for shape forming are primarily shown for lenses. Preforms of lenses or prisms can be produced by compression molding, where a certain volume of molten glass is formed in adequate molds. Preshaping describes the process of making blanks or preforms from the raw material, generally glass. Cutting is the first step of classical optics manufacturing; blanks of optical components are cut out of glass blocks or bars supplied by glass manufacturers. During cutting, the glass block or bar is attached to the saw base, which consequently acts as work piece holder. Finish grinding is applied in order to remove or minimize the subsurface damage layer and microcracks induced by precedent rough grinding and to reduce the surface roughness to achieve a polishable surface. Lens or prism blanks can be manufactured by cutting and subsequent rounding or hollow drilling where necessary.
