| 摘要 |
An optical arrangement, in particular a microlithographic projection printing installation, has in particular a slot-shaped image field or rotationally non-symmetrical illumination. A refractive optical element, e.g. a lens (2), is heated by the rotationally non-symmetrical radiated impingement (3) of a light source. At least one electric heating element is coupled to the optical element. Said heating element comprises a resistance heating coating carried by the optical element. In the region of the surface (3) of the optical element acted upon by the radiation of the light source the resistance heating coating is substantially optically transparent. It comprises a plurality of parallel, electrically mutually insulated coating strips (5 to 10). A heating current source (17 to 19) is additionally part of the heating element. By virtue of the combined heating of the optical element by the radiated impingement (3) and the resistance heating, a correction of imaging defects induced by illumination in the optical element is achieved by means of a symmetrical and/or homogeneous temperature and refractive index distribution.
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