Optical system for a lithographic projection exposure apparatus

An optical system, comprising:

• an illumination optical unit configured to guide illumination light to an object field in which a structured object is arrangeable, the structured object comprising one-dimensional object structures, the illumination optical unit configured so that the object field illuminated by the illumination optical unit has a first field extent along a first field coordinate and a second field extent along a second field coordinate perpendicular to the first field coordinate, the second field extent is less than the first field extent, the illumination optical unit configured so that the illumination light impinging on the object field is polarized in a polarization direction that extends parallel to the second field extent along the second field coordinate;
• and
• a projection optical unit configured to guide the illumination light and imaging light from the object field toward an image field in which a substrate is arrangeable and onto which the one-dimensional object structures of the structured object are intended to be imaged,
• wherein:
• the optical system is configured to generate one-dimensional image structures by imaging the one-dimensional object structures of the structured object;
• and
• the projection optical unit has an exit pupil in a pupil plane having a pupil aspect ratio between a first pupil extent in a longitudinal direction and a second pupil extent in a transverse direction that is greater than 3.