OPTICAL BEAM DEFLECTING ELEMENT AND METHOD OF ADJUSTMENT

摘要

An optical beam deflecting element (BDE) for generating a radiation beam having rays according to a predefined angular distribution by changing an angular distribution of rays in a radiation beam incident on the beam deflecting arrangement comprises first deflecting structures arranged in a first deflecting region (DR1) generating a first bundle of first rays, each of the first rays having a propagation direction corresponding to a ray angle within a predefined distribution of ray angles, the first rays having first intensities according to a first intensity distribution; and second deflecting structures arranged in a second deflecting region (DR2), laterally offset relative to the first deflecting region, generating a second bundle of second rays, each second ray having a propagation direction corresponding to a ray angle within the predefined distribution of ray angles, the second rays having second intensities according to a second intensity distribution, which differs from the first intensity distribution. The beam deflecting element may be used effectively as an energy distribution manipulator in an illumination system to vary the energy distribution within a given spatial intensity distribution in a pupil plane (PILL) of the illumination system substantially without changing the shape and size and position of illuminated areas in the pupil plane.