Open AccessComparative assessment of freeform polynomials as optical surface descriptions
Author(s) -
Ilhan Kaya,
Kevin P. Thompson,
Jannick P. Rolland
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.022683
Subject(s) - zernike polynomials , polishing , conic section , diamond turning , optics , orthogonal polynomials , fabrication , computer science , robustness (evolution) , polynomial , surface (topology) , mathematics , materials science , diamond , geometry , wavefront , physics , mathematical analysis , medicine , biochemistry , chemistry , alternative medicine , pathology , composite material , gene
Slow-servo single-point diamond turning as well as advances in computer controlled small lap polishing enables the fabrication of freeform optics, or more specifically, optical surfaces for imaging applications that are not rotationally symmetric. Various forms of polynomials for describing freeform optical surfaces exist in optical design and to support fabrication. A popular method is to add orthogonal polynomials onto a conic section. In this paper, recently introduced gradient-orthogonal polynomials are investigated in a comparative manner with the widely known Zernike polynomials. In order to achieve numerical robustness when higher-order polynomials are required to describe freeform surfaces, recurrence relations are a key enabler. Results in this paper establish the equivalence of both polynomial sets in accurately describing freeform surfaces under stringent conditions. Quantifying the accuracy of these two freeform surface descriptions is a critical step in the future application of these tools in both advanced optical system design and optical fabrication.