Polarization independent visible color filter comprising an aluminum film with surface-plasmon enhanced transmission through a subwavelength array of holes

The enhanced transmission through periodic arrays of sub-wavelength holes in optically-thick metallic films has many potential applications, such as in wavelength filters, light extraction from light emission diodes, and subwavelength photolithography. A color filter comprising arrays of subwavelength holes in an aluminum film has been fabricated. In addition to the simplicity of the process, the aluminum film enables the excitation of visible-range surface plasmons due to its high plasma frequency. Periodic nanostructures in the aluminum film open the way for new visible color filters. (C) 2011 American Institute of Physics. [doi:10.1063/1.3560467]