| 摘要 |
A refractive projection objective for use in microlithography with lenses made exclusively of one and the same material has an image-side numerical aperture larger than 0.7. A light bundle defined by the image-side numerical aperture and by the image field has within the objective a variable light-bundle diameter smaller than or equal to a maximum light-bundle diameter. In a length interval measured on the optical axis from the system diaphragm towards the object field and at least equaling the maximum light-bundle diameter, the variable light-bundle diameter exceeds 85% of the maximum light-bundle diameter.
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