| 摘要 |
The invention relates to a projection lens (1) for short wavelengths, in particular, for wavelengths lambda< 157 nm, provided with several mirrors (M1, M2, M3, M4, M5 and M6), arranged in a precise position with relation to an optical axis (5). The mirrors (M1, M2, M3, M4, M5 and M6) comprise multi-layer coatings. At least two different mirror materials are provided which differ in the rise in thermal expansion coefficient as a function of temperature around the zero transition of the thermal expansion coefficient, in particular, in the sign of the value. |
