| 摘要 |
An illumination system for a projector unit for microlithography working with ultra-violet light, has an angle-retaining light mixer with at least one integrator rod comprising an inlet surface for receiving light from a light source and an output surface for output of emergent light mixed by means of the integrator rod. At least one prism arrangement for receiving emergent light and for changing the polarisation state of the emergent light is arranged in series after the integrator rod. A preferred prism arrangement has a polarisation distribution surface arranged perpendicular to the propagation direction of the emergent light which permits the unhindered transmission of light components with p polarisation and reflects components with s polarisation. The separated beams with orthogonal polarisation are brought parallel by means of a mirror surface arranged parallel to the polarisation distribution surface and the same polarisation state for both partial beams is achieved by means of a suitable retarder. |
