The Carolina Flashers  Photonics Group is a North Carolina-based organization of worldwide Amateur Radio operators who use coherent, or more often, partially coherent light as a communications medium. We are proud to be affiliated with the ARRL, and our club callsign is K4THZ.
According to Federal Communications Commission regulations, the frequencies above 300GHz are a legitimate allocation for the Amateur Radio Service.  This includes light waves, of course.  While many people consider through-the-air optical communication to be an unregulated medium, we as licensed hams follow all applicable FCC Part 97 rules, such as callsign IDs, no commercial messaging, etc.
Clint (KA7OEI) and Chris (VK3AML, visiting from Australia) have a free-space-optical QSO at the Yucca Valley, California QTH of Bob (W6QYY)
Watch this space as our group expands and our website evolves. Some of our goals are:
Local multimedia communication
DX (long distance) communication
Networked optical repeaters in the area
Inexpensive, easily duplicated equipment
Exceptional ham radio fun and fellowship
Listed below are links to some relevant information on this subject:
ARRL - the national association for Amateur Radio™