Wavefront Aberration Function

Abstract

Abstract In this paper we obtain equations for the two aperture second derivatives of the wavefront aberration function in terms of the position of the local sagittal and tangential foci. The derivatives presented here are valid for meridional rays. The local foci positions for any tangential aperture zone are calculated by tracing one ray that corresponds to that zone and using Coddington's equations. The second derivative equations can be incorporated in the usual procedure of aberration computation, increasing from two to four the number of equations available for each tangential ray traced.