Free-space optical transmission is a thing, though it's environmentally quite challenging. We tested some gear from https://www.koruza.net at the Internet Archive ~10 years ago or so (I've also built some 10G point-to-point links in my garage, though I'd hardly call them reliable). It is pretty cool to see a scratch build rather than using commercial transceivers
> Brashears also said Starlink’s laser system was able to connect two satellites over 5,400 kilometers (3,355 miles) apart. The link was so long “it cut down through the atmosphere, all the way down to 30 kilometers above the surface of the Earth,” he said, before the connection broke.
30k would be about 1/3rd MSL air pressure, so that's pretty thin relative to what humanity experiences. Also note it says 'connection broke', not that the connection was way way slower than it would be in a vacuum.
There's this thing called wind that can move your outdoor installations quite a bit ;)
I'd call it a wash, space is hard, but so are atmospheric interactions, weather, foliage, and all the side effects of human habitation (like someone building a house in the middle of your laser link, yes that happens.)
Atmospheric scintillation is the barrier for free space laser communications on terra-firma; this is one reason we enclose the laser light in optical fibre to avoid this problem.
In space where nobody can hear you scream, scintillation isn't a problem.
About 25-30 years ago we had an FDDI network, and the hosts had optical bypass switches on them.
The FDDI network comprised two fiber rings, one going clockwise and the other anticlockwise. If a host dropped off the network, the optical bypass switch would loop the two rings to each other, creating one big ring. Two non-adjacent hosts dropping off the network would break the ring.
The optical bypass was surprisingly simple. It was a couple of pieces of fiber segment glued to a swiveling magnet; an adjacent electromagnet pull the magnet/fiber assembly, connecting the network rings normally if energized. If power were removed from the electromagnet, a spring would pull it in the other direction, pointing the fibers into loop position, connecting the network rings in looped configuration.
In both cases, the air was the medium between the fibers entering the switch and the straight-through/loopback fiber segments.
Yes and no, worth reading in to. Yes in the sense of, technically laser but gets reconverted along the path in many ways, ethernet turning it in to frames after a receiver (modem, whatever equipment) then translates it.
Laser = over air, susceptible to interference like atmospheric things, dust, flies, also; since it's laser and over a distance, the photons will spread out. Beam divergence.
Fiber lines are carefully engineered to contain the light transmission to get it to where it has to go.
Microwave would be better than laser to my knowledge but then your packets are flying around through the air willy nilly. Things like SSL handshakes and unencrypted hello packets are readable.
Also this uses air as the medium.