Optimized design of the optical filters inside integrated color pixels (ICPs) for complementary metal-oxide semiconductor image sensors requires analytical models. ICP optical filters consist of subwavelength patterned metal layers. We show that a one-mode model, in which subwavelength gaps in the metal layer are described in terms of single-mode waveguides, suffices to predict the salient features of measured ICP wavelength selectivity. The Airy-like transmittance formula, derived for transverse-electric polarization, predicts an angle-independent cutoff wavelength, which is in good agreement with predictions made with a two-dimensional finite-difference time-domain method.
© 2004 Optical Society of America
(050.0050) Diffraction and gratings : Diffraction and gratings
(050.2770) Diffraction and gratings : Gratings
(110.2970) Imaging systems : Image detection systems
(130.3120) Integrated optics : Integrated optics devices
(260.2110) Physical optics : Electromagnetic optics
Peter B. Catrysse, Wonjoo Suh, Shanhui Fan, and Michael Peeters, "One-mode model for patterned metal layers inside integrated color pixels," Opt. Lett. 29, 974-976 (2004)