Ultra-thin plasmonic color filters incorporating free-standing resonant membrane waveguides with high transmission efficiency.

We propose an ultra-thin plasmonic color filtering device based on subwavelength metal grating engraved on a dielectric membrane waveguide without substrate. As experiments demonstrate, the fabricated free-standing plasmonic color filters have more than 70% transmission efficiency at different resonant wavelengths in the visible spectral region and are capable of generating arbitrary colors. Experimental results are in good agreement with the theoretical calculations. These artificial nanostructured color filtering devices may find potential applications in high resolution color imaging and sensing systems. [ABSTRACT FROM AUTHOR]