Visible color routing metasurface using dual focal phase profile in green light

As an increased demand in high resolution display, the pixel size in the image sensor is reduced to increase the resolution. Although there have been recent studies on metasurface color routers to overcome the limitation of the conventional image sensor, there are still limitations in that the designed devices do not show the advantages of router or are difficult to fabricate. In this study, the fabricable metasurface that distribute three visible wavelengths to each targeted color sensor is proposed numerically. For the distribution like the Bayer pattern, a dual focal phase profile is utilized for green color. The designed metasurface size is 2 μm by 2 μm, and the routing efficiencies are 12 %, 25 %, and 30 % for 473 nm, 532 nm, and 660 nm, respectively, where the performance in red light exceed the fundamental limit of efficiency of the conventional Bayer color filter array.