SPATIAL FREQUENCY FILTER DEVICE FOR USE WITH A LASER BEAM, SPATIAL FREQUENCY FILTER ASSEMBLY HAVING SUCH A SPATIAL FREQUENCY FILTER DEVICE, AND METHOD FOR SPATIAL FREQUENCY FILTERING OF A LASER BEAM

摘要

The invention relates to a spatial frequency filter device (100) for use with a laser beam (200), comprising a neutral region (110), which is designed to transmit or to reflect the laser beam (200), and a deflection region (120) which radially adjoins the neutral region (110) and is designed to deflect beam components (210) of the laser beam (200) from a beam axis (A) of the laser beam (200). The deflection region (120) has a constant portion (123) in which a deflecting effect on the beam components (210) of the laser beam (200) for each location in the constant portion (123) is independent of a distance of the location from the neutral region (110), and the deflection region (120) has a varying portion (125) in which the deflecting effect on the beam components (210) of the laser beam (200) varies according to a distance from the neutral region (110).