Transmissive color shift through layered sub-wavelength gratings based on plasmon enhanced coupling

This paper presents a new principle of color changing pixel by controlling the boundary condition for the surface plasmon polariton resonance on a metallic micro/nano mechanical device. A nanometric wire-grid polarizer was developed by the electron-beam patterning of 100 nm thick aluminum on glass; a pair of such polarizers was stacked with a sub-micron gap, and the separation or the in-plane rotation alignment angle was mechanically controlled to tune the coloration of the transmission light in the visible wavelength range. FDTD simulation indicated that the polarization-dependent spectrum had an effect to choose the transmitting peak wavelengths from the white backlight.