Well, we've already got the beginnings of visible light nano-antennas (https://en.wikipedia.org/wiki/Optical_rectenna https://en.wikipedia.org/wiki/Optical_rect

Well, we've already got the beginnings of visible light nano-antennas (https://en.wikipedia.org/wiki/Optical_rectenna https://en.wikipedia.org/wiki/Optical_rectenna). I'm not sure how directional they are, but we do have MEMS cantilevers to point them individually. Granted, getting this all working together as a combined camera/monitor is the kind of thing that could keep a generation of engineers and scientists occupied, with no guarantee of success.