Reinhold Bittner

Design And Holographic Production Of Aberration-Corrected Synchrotron Diffraction Gratings

An improved method of optimizing the focal properties of holographic synchrotron diffraction gratings for use in normal and grazing incidence monochromators is presented. Generation of holographic line patterns on spherical blanks by aspheric wave interference considerably reduces the main aberrations of classic Rowland-type gratings. Especially in grazing incidence, the correction of coma at two points in the spectral range (4 to 12 nm) yields a substantial increase of spectral resolution. Super-smooth surfaces of blanks and interferometer elements together with an elaborate photo resist and ion beam etching technology are the main requirements for the generation of such high-performance diffraction gratings.