Fabrication and testing of high quality small germanium plano-convex lens

In this paper, a new method is designed which is accurate (λ/4, λ=632·8 nm) for finishing the small (less than 2·6 mm diameter and a center thickness of 0·4 mm) and soft germanium plano-convex lens. Special features of this process are as follows: (i) it produces a scratch-free and smooth surface; (ii) a precision blocking jig has been constructed which enables the operators to engage centering work of the plano-convex lenses (i.e. the lenses edge are co-axial with the optical axis); (iii) a modified moiré technique rapidly performs the centering test; and (iv) the simulation model has been developed for evaluating the polishing parameters used in this process.