Fly's eye condenser and illumination system therewith

Abstract

A fly's eye condenser (15) for converting an input light distribution into an output light distribution has at least one raster arrangement of optical groups (21, 22), of which at least some comprise polarization-changing means (30) suitable for changing polarization. The polarization-changing means include at least one layer of birefringent material associated with an optical group. The layer of birefringent material of at least two optical groups has a different thickness in a passage direction of the light. The fly's eye condenser thus permits specific, location-dependent control of the polarization state of the output light distribution. If the fly's eye condenser is used in an illumination system (10), then it can be used not only to homogenize the light distribution on the illumination plane of the illumination system but, at the same time, a location-dependent or angle-dependent polarization distribution can also be set in the illumination plane.

Dependencies are inferred from the claim text.