Projection lens of a microlithographic exposure system

A projection lens having an optical axis, the projection lens configured to image radiation from an object plane of the projection lens to an image plane of the projection lens, the projection lens comprising:

• a plurality of refractive lenses of non-optically uniaxial material, at least one of the plurality of refractive lenses having intrinsic birefringence;
• and
• at least two compensation elements configured to at least partial compensation of the intrinsic birefringence, each of the at least two compensation elements comprising a respective optically uniaxial crystal material,
• wherein:
• at least one of the at least two compensation elements does not introduce a retardation for light passing through in a direction of the optical axis;
• and
• the at least two compensation elements are arranged along the optical axis at different positions, between which there is at least one of the plurality of refractive lenses.