Home – Home – Jornals – Avtometriya 2005 number 1

Certification of diffractive optical elements (DOE) used for aspherical surface testing is considered. The research is concerned with the methods of combining two phase transmission functions in a single DOE in order to form a spherical wavefront in addition to the main aspherical wavefront, whose measurement results can be used to certify the aspherical wavefront. DOE with two diffractive structures combined by dividing the aperture of the element into cells that are alternatively filled with fragments of the structures is analyzed. Three versions of cell shapes are considered, namely, rings, stripes and annular sectors. It is theoretically and experimentally shown that for the configuration with annular sectors the introduced errors are less than in the case of the configuration with rings or stripes. The influence of the cross-talk interference in the case of close spatial frequencies on the error of interference measurement of spherical and aspherical wavefronts is numerically calculated and the ways to reduce it are proposed.