Abstract

The fabrication of miniaturized refractive prisms for the use in free space optical systems is a relatively new field in component fabrication^1,2,3. Thermal imprinting in PMMA has reduced flexibility in the angle choice and induces stress in the substrate. The optical quality of the surface is given by the quality of the master¹. Synchrotron or proton irradiation of PMMA gives the advantage of arbitrary deflection angles of prisms with depths of several hundred microns. Problems arise from the fact that the roughness of a thick metal mask (>20µm) is directly copied into the prism surface^2,3. This paper describes a new fabrication technique for deflection elements whose surface quality is better than the mask’s: the surface roughness is better than 20 nm. The method is based on deep proton irradiation; the new idea is that during irradiation the sample is moved relative to a fixed mask. By this a polishing effect of protons in the prism surface occurs yielding the above mentioned smoothness.

© 1995 Optical Society of America