Investigation of filter size and duty ratio on transmission color filter based on surface plasmons

In this paper, we discuss a minimum filter size and duty ratio (= width/period) of a subwavelength Al grating for a tunable RGB color filter based on surface plasmons. An array of Al gratings was deployed over a through hole by sacrificial release process. The peak wavelength of the transmitted light was red-shifted by increasing the period of the subwavelength grating from 450 nm to 600 nm. We obtained enough transmission light intensity from the 10 μm square pixel-size including 20 Al nanowires. The noise-level was found to be dependent on the duty ratio and decreased with increase of the duty ratio.