Contributions to the Optics of Mirror Systems and Gratings with Oblique Incidence I Ray Tracing Formulas for the Meridional Plane*

General ray tracing formulas have been developed for the “meridional plane” of noncentered optical systems consisting of imaging mirrors and gratings. It has been assumed that all centers of curvature of object and image field and of the aperture diaphragm lie in the meridional plane and that the grooves of a grating are perpendicular to that plane. The ray-tracing formulas have been simplified for a general ray with only small deviations from the instrument axis (zero ray). The influence of a change of diffraction for curved gratings has been included.