title: Monochromatic aberrations in resonant optical elements applied to a focusing multilevel reflectarray.
abstract: The monochromatic aberrations produced by the phase distribution reflected by resonant sub-wavelength metallic structures are studied both analytically and numerically. Even for normal incidence, the angular dependence of the re-radiated wavefront disturbs the overall performance of the reflectarray. This effect is modelled as combination of a linear and a cubic dependence. A complete numerical simulation of a multilevel focusing reflectarray is performed using computational-electromagnetic and physical-optics-propagation methods. A modified Strehl ratio is defined to show the dependence of the focused spot behavior on aperture. The irradiance distribution is dependent on the polarization state. A small-aperture focusing reflectarray has been designed, fabricated, and tested. The irradiance distribution at the focusing plane is compared with the simulated one, showing a good agreement when residual wavefront aberrations are included.
authors.affiliation: CREOL, University of Central Florida, 4000 Central Florida Blvd. Orlando, FL 32816-2700, USA.
authors.forename: James
authors.initials: J
authors.lastname: Ginn
authors.forename: Javier
authors.initials: J
authors.lastname: Alda
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Gómez-Pedrero
authors.forename: Glenn
authors.initials: G
authors.lastname: Boreman
mesh_terms: D016477:Artifacts; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D008962:Models, Theoretical; D010783:Photometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation