title: Subwavelength-grating-induced wavefront aberrations: a case study.
abstract: The on-axis wavefront aberrations of a one-dimensional subwavelength-grating antireflection coating on an f/1.7 lens surface are shown to be small with noticeable contributions of defocus, astigmatism, and piston. The astigmatism is 0.02 wave, and the magnitude of the piston approaches one wave peak-to-valley. The difference in aberrations between orthogonally polarized wavefronts, or the retardance aberration, shows 0.01 wave of astigmatismlike variation and more than 0.01 wave of retardance-induced defocuslike variation. A small coupling between polarization states occurs in the form of the familiar Maltese cross, yielding a maximum of 3% coupling in the four diagonal edges of the pupil.
authors.affiliation: College of Optical Sciences, University of Arizona, Tucson, AZ 85721-0094, USA. kcrabtree@optics.arizona.edu
authors.forename: Karlton
authors.initials: K
authors.lastname: Crabtree
authors.forename: Russell A
authors.initials: RA
authors.lastname: Chipman