Polarization sensitive photodiodes
In this paper, we present the design, fabrication, and characterization of wire grid polarizers. These polarizers show high extinction ratios and high transmission with structure dimensions that are compatible with current complementary metal-oxide-semiconductor(CMOS)technology. To design these wire grids, we first analyze the transmission properties of single apertures. From the understanding of a single aperture, we apply a modal expansion method to model wire grids. The most promising grids are fabricated on both a glass substrate and CMOS photodiode. An extinction ratio higher than 200 is measured.
In a collaboration with the Centre Suisse d'Electronique et Microtechnique (CSEM) we have integrated plasmonic structures on the top of photodiodes.
In particulare, the design, fabrication, and characterization of wire grid polarizers has been investigated. These polarizers show high extinction ratios and high transmission with structure dimensions that are compatible with current complementary metal-oxide-semiconductor (CMOS) technology. To design these wire grids, we first analyze the transmission properties of single apertures. From the understanding of a single aperture, we apply a modal expansion method to model wire grids. The most promising grids are fabricated on both a glass substrate and CMOS photodiode. An extinction ratio higher than 200 is measured.
Figure 1: (a) Calculations of p-polarized zero order transmission of wire grids (h=285 nm and w=150 nm) for period varying between 350 and 600 nm (c) and corresponding measurements. The inset in panel (c) is a SEM image of the wire grid with p=600 nm. (b) p- and s-polarized zero order transmission spectra (d) and the corresponding extinction ratio for p=500 nm, h=285 nm, and w=150 nm. Black solid curves: experiment; red dashed curves: calculation.
Check the corresponding publication: PDF External link: doi: 10.1063/1.3133862