So you are correct, of course. I meant to use 1000nm, not 100nm. However, the thing about being in space is you actually COULD use vacuum UV (including 100nm) which doesn’t propagate in fiber and is even blocked by air. Not only does that have the bandwidth advantage but also allows even smaller apertures (or greater gain for the same aperture). Of course, vacuum UV transceivers aren’t really available (you can get coherent UV lasers down to 126nm) but in the long term it is possible.

Hah, oops. 3e-15s period, not 3e-16s. You’re right. What’s an order of magnitude between friends? (Won't let me edit the original post.)