Hyperbolic holographic gratings: analysis and interferometric tests.

The aberrations of hyperbolic diffraction gratings produced with two spherical waves are analyzed theoretically and experimentally. The behavior of these gratings in collimated illumination indicates that for a grating of a given size there is a critical spatial frequency above which the aberration remains constant for all spatial frequencies. Aberrations associated with geometrical errors in the recording geometry are derived. With simple interferometric tests, misalignments in the recording process can be identified easily.