Light wave communication

Yesterday I mentioned that some years ago I bought some Flatlights (very high power LEDs) to allow me to get further over the horizon with light beam communication. Even with quite low powered LEDs I was able to achieve quite decent ranges non-line-of-sight. 

Optical communications is accessible to all and is ideal for homebrewing. All my gear was homemade and all software was free. Also, only very simple test gear is needed. As I recall a multimeter and a bearly lit LED in a dark room is about all you need. This is much simpler than microwaves. 

There is so much to be learned about optical communications. My "thing" was detecting weak signals over the horizon using PC software. What amazed me was there was no sign of the light in the sky, yet the signals were perfectly detectable on the PC as long as the RX was aimed in the right direction. I am sure much further would have been possible.

See https://sites.google.com/site/g3xbmqrp3/optical