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.
© 2007 Optical Society of America
Original Manuscript: December 20, 2006
Manuscript Accepted: February 7, 2007
Published: September 5, 2007
Minfeng Chen, Hung-chun Chang, Allan S. P. Chang, Shawn-Yu Lin, J.-Q. Xi, and E. F. Schubert, "Design of optical path for wide-angle gradient-index antireflection coatings," Appl. Opt. 46, 6533-6538 (2007)