I've heard about different optical wireless... they are based on different ideas.
For example:
1) there are wireless optical headphones: they use modulated infrared light. I didn't tested these factory made headphones, but have made such headphones with my hands. They were very sensitive to artificial sources of light, especially old lamps.
2) there are wireless optical stations for transferring data: they uses laser and they have some disadvantages:
a) they (both receiver and transmitter station) should be justified thoroughly and fixed tightly, to avoid loses of connection because of wind.
b) they are very sensitive to bad weather (rain, snow, fog).
