title: Design of optical path for wide-angle gradient-index antireflection coatings.
abstract: What we believe to be a new principle is introduced for the design and selection of gradient-index antireflection profiles that are effective over a wide range of incident angles as well as wavelengths at a given physical film thickness. It is shown that at oblique incidence the smoothness of the optical path of incident light inside a gradient-index film has a crucial effect on the overall reflection. Thus the smoothness of variations in refractive angle (rather than that of the index profile itself) needs to be maximized for wide-angle operation. As an example, the performance of Gaussian and Quintic profiles at large incident angles are considered in light of this point of view.
authors.affiliation: Graduate Institute of Electro-Optical Engineering, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Minfeng
authors.initials: M
authors.lastname: Chen
authors.forename: Hung-chun
authors.initials: HC
authors.lastname: Chang
authors.forename: Allan S P
authors.initials: AS
authors.lastname: Chang
authors.forename: Shawn-Yu
authors.initials: SY
authors.lastname: Lin
authors.forename: J-Q
authors.initials: JQ
authors.lastname: Xi
authors.forename: E F
authors.initials: EF
authors.lastname: Schubert