Tailoring the directional characteristic of a ground glass screen with a DOE

The angular spectrum of the scattering process of a ground glass surface scatterer is much narrower than that of a volume scatterer. It holds that the more close grained the surface is the smaller is also the angle of half maximum of intensity. With a diffractive optical element (DOE) it is possible to manipulate the directional characteristic thus making it possible to use a close grained scatterer but have a large angle of half maximum. This is useful when the radiation characteristic of the incident light has to be destroyed, e.g. if the ground glass is used as an imaging screen. We present a Hartmann test setup for spectacle lenses where an axicon behind the ground glass is used to get a more uniform intensity distribution over the aperture.