Retrotechtacular: First laser transmitter built 50 years ago article tells about a hack is as cool today as it was fifty years ago. It was an experiment performed May 3rd and 4th, 1963, which involved sending data (audio in this case) over long distances using a laser. The team had to hack together everything for themselves. They built their own helium-neon laser tube (just a few months after the invention of the visible Helium-Neon Gas Laser).
50 years since project “Red Line” page tells how this distance record (119 miles) for laser-beam communications was done.