To the extent that air is not transparent, this doesn't work.
and does cause beam scattering.
This does not address beam scattering. If the air is scattering the laser beam, it still scatters the beam.
by creating a refractive channel like this they absolutely will reduce beam dispersion.
It would reduce beam spread... except that the beams that create the channel are not themselves channeled.
obviously it doesn't eliminate beam spread
on this we agree
but even a fiber channel perfectly designed for a single mode will have some diffusion so whats your point?
My point is that from a surface-level analysis, it doesn't do anything useful.
they may be able to increase snr by 10^4 over current technologies at 100 m. that's a serious improvement that shouldn't simply be dismissed so thoughtlessly.
Let me repeat. The beams that create the channel are not themselves channeled. So the channel itself... has the diffraction, scattering, and beam spread of an unchanneled beam. The net result can't be better than an unchanneled beam, because it is made out of an unchanneled beam.