Fig. 6: Two-subpixel flat-optics colour display: idea and design.
a, b Basic working principle of current LCD/OLED colour technologies based on three red, green and blue (RGB) subpixel colour transmission units. c Proposed flat-optics technology based on two polarization-controlled subpixels A and B. d, e ALFRED designs of A and B (3D brown boxes with grey unit cells) with the chromaticity gamut contained in (d) and exceeding (e) the standard RGB colour space (dashed yellow line). In panels d, e, the chromaticity obtained when the input light varies between TEx and TMx polarizations for samples A and B is indicated as a solid thick black line, while the total gamut obtained by mixing the two subpixels is the four-point rhomboid delimited by the black lines
