ANALYSIS OF GRATING LENS ABERRATION

A method that approximates a diffraction formula to the Fourier integr al formula by the application of a coordinate transformation is propos ed, and it is proved to be a superior and more accurate approximation when it is applied to focusing systems under a nonsine condition. Base d on this approximation, the condition that gives the diffraction focu s position is derived by the application of two methods. The first is applicable to rotationally symmetrical aberrations such as spherical a berration, and the second is a more general method that utilizes the s tandard deviation of a wave aberration. These methods are actually app lied to a grating lens as a way to study both chromatic aberration cha racteristics and oblique incidence characteristics.