Wavefront aberration determination in non-axially symmetrical optical systems

Non-axially symmetrical optical systems can provide better solutions to several optical design problems. However, determining their wavefront aberrations is challenging due to the great diversity of their configurations. Accordingly, in the present study, the optical path length (OPL) between two boundaries in a non-axially symmetrical system is expanded by a Taylor series expansion with respect to the base ray. This expansion converts the OPL from a deep composite function to a polynomial form. The various order wavefront aberrations are then obtained from the coefficients of the polynomials in terms of the system independent variables. The proposed method is equally valid for axially symmetrical systems provided that the object is placed on the meridional plane. Overall, the method provides a systematic approach for analyzing the wavefront aberrations in a wide range of optical systems.