BEAM SHAPING APPARATUS AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To obtain a high-performance beam shaping apparatus with which the nonuniformity of a sectional surface strength distribution by diffraction accompanying propagation hardly occurs by providing the boundary portion between the shutting portion and non-shutting portion of a beam shutting means with an intermediate zone where transmissivity changes spatially continuously and gently. SOLUTION: The beam shutting means 3A formed by applying multilayered dielectric films on the surface of a transparent plate, such as optical glass 3a, is provided with the intermediate zone 3d where the transmissivity changes gently in continuation with the boundary portion between the shutting portion 3c for part of the beams and the non-shutting portion 3b for part of the beams. In addition, the beam shutting meams 3A is provided with a wave front correcting means for correcting the distortion of the wave front of the beams transmitted through the means and shaping the beams. The intermediate zone 3d is formed by vapor deposition of the multilayered dielectric films by changing film thicknesses in such that manner that the transmissivity changes continuously and gently from the total transmission to total reflection i.e., from 100% to 0% in the region held by the non-shutting portion 3b and the shutting portion 3c.