Planar metallic nanoscale slit lenses for angle compensation

Abstract

We demonstrate numerically, using a modified total-field/scattered-field formalism, that metallic lenses, based on arrays of nanoscale slits with varying widths in a planar metallic film, can be used to focus light and compensate for various angles of incidence. These structures could be used as integrated microlenses to improve the efficiency of pixels in solid-state image sensors. Our design guidelines simultaneously accomplish a prism and focusing action. Our results also indicate the importance of the aperture effect for such far-field focusing devices.