front view .full face .Janus-like Metasurface Technology that Acts According to the Direction of Light. Like the Roman god Janus with two faces, this metasurface shows entirely different optical responses depending on the direction of incoming light, effectively operating two independent optical systems with a single device (for example, a metasurface that acts as a magnifying lens in one direction and as a polarized camera in the other).  --ar 3:2