title: Sommerfeld revisited: a new approach to the third-order Seidel aberrations.
abstract: In following a suggestion of Sommerfeld, who was able to derive the paraxial properties for points on the optic axis from the existence and continuity of wave fronts satisfying the eikonal equation, it will be shown how the whole set of the third-order Seidel aberrations of a centered optical system made of refracting surfaces of revolution can be obtained if the series expansion in the radial coordinates is continued up to the fourth order.
authors.affiliation: Department of Physics, Istituto Nazionale per la Fisica della Materia, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy. pozzi@df.unibo.it
authors.forename: Giulio
authors.initials: G
authors.lastname: Pozzi