Great example in the long, varied history of communication devices going back to the ancients, but really picking up speed in the Renaissance. For more example of interesting optical communication devices I recommend Deep Time of the Media by Zielinski (it includes lots of pictures too!):http://mitpress.mit.edu/books/deep-time-media
When I was a kid I had a a kit for doing this.
This also the principal behind spying on someone in a room by watching the wobble of reflected light on a window.
A few groups of HAM Radio operators have been experimenting with what they call terahertz communication for quite some time now.
The transceivers got pretty sophisticated, with very complex optics. There are reports of successful conversations over distances of >150km.
Apparently, many of them are in Germany so quite a few of the sources are in German.
http://modulatedlight.org/optical_comms/optical_index.html
http://www.db6nt.de/laser.html
http://modulatedlight.org/optical_comms/SDIM8379h.jpg
Bell invented this too?! Was this before or after the telephone?
In 1972, Gary Starkweather (inventor of the laser printer) rigged up a laser-based data link with 35 megapixels/second bandwidth because Xerox Parc was split across two buildings: one with the controller and one with the marking engine for his printer. See page 42 of http://www.computerhistory.org/collections/catalog/102702465 .