Optimizing Plasmonic Color Filter for Imaging Sensor

In this paper, a double-side bull’s eye plasmonic color filter used in complementary metal oxide semiconductor (CMOS) based standard imaging sensors is presented. The thin-film filter is silver-made and optimized by using a particle swarm algorithm in order to modify the corrugation period, duty cycle, film thickness, grating height and aperture diameter for infrared imaging. The filter is designed for central wavelength 835 nm, having the maximum transmittance of 38.6 % and the full width at half maximum (FWHM) of 110 nm. Inexpensive implementation, proximity to the sensitive region, reduced crosstalk and independence from  temperature-sensitive polymers, are some of the advantages of this filter, making it suitable for tough temperature conditions. Moreover, using functional analysis of this plasmonic filter and comparing it to the optical filters with similar central wavelength has led us to the investigation of surface plasmon features under a local electric field intensity distribution.