| 摘要 |
<p>The invention concerns an optical system and a method of characterising an optical system, in particular in a microlithographic projection exposure apparatus. According to an aspect, an optical system having an optical axis (OA) comprises a first element (111, 416, 516) which is partially translucent for light of a working wavelength of the optical system and has at least one partially reflecting first surface arranged rotated about a first axis of rotation in relation to a plane perpendicular to the optical axis (OA), a second element (121, 418, 518) in succession to said first element along said optical axis (OA) which is partially translucent for light of the working wavelength and has at least one partially reflecting second surface which is arranged rotated about a second axis of rotation in relation to a plane perpendicular to the optical axis (OA), and an intensity measuring device (112, 122, 417, 419, 517, 519) for measuring the intensity of light reflected at the first surface and the intensity of light reflected at the second surface.</p> |
