Alternative method for computing primary wavefront aberrations using Taylor series expansion of optical path length

This work proposes a methodology for computing the primary wavefront aberration coefficients of axis-symmetrical optical systems by expanding the optical path length of a general ray using the Taylor series expansion. The obtained values of the wavefront aberration coefficients are compared with those determined from Zemax simulations. It is shown that the corresponding numerical results are in excellent agreement with those obtained from Zemax simulations.