Abstract

Ion beam figuring is a noncontact technique for the final shaping of precision optical components. Its use has in the past been primarily restricted to planar and near planar surfaces. To extend the application of ion beam figuring to steeply curved surfaces and surfaces with large saggital depth requires further development of the theoretical model. In this paper, the propagation and sputtering properties of the ion beam produced by a common ion source are modeled. The effects accounted for include: (1) beam current loss during transit from the ion source to the surface, (2) divergence of the ion beam during transit, and (3) influence of the beam/surface geometry on the sputter yield and the material removal profile. The model is then tested experimentally by performing ion beam milling tests on optical components in configurations that are inexpensive, easy to test, and yet strongly exhibit the effects of steep surface geometries.

© 1991 Optical Society of America