Light Broadcasting

How about the next thing in technology?

Lights have a lot of potential, I mean ordinary incandescent lighting whether outside or inside. 

FM, with regard to radio, stands for Frequency Modulation. It requires a higher frequency than AM, which stands for Amplitude Modulation. This refers to the way in which information, such as sound or music, is encoded onto the carrier wave. Frequency Modulation means that the frequency of the basic carrier wave is varied to match the sound from the microwave, and then it gets turned back into sound by the radio receiver.

The same principle could apply to visible light. Aside from seeing light with our eyes we could also encode information on it in the same way as with radio waves. This hasn't been done for two reasons. First there is apparently no reason to use technology because we can already see light with our eyes. Second is that the range of light is strictly limited to line of sight while radio can be received by an antenna mounted at a height and longer wavelengths of radio can reflect off the ionosphere. Light does have the advantage over radio that it is of higher frequency than radio and can thus carry more information if we use frequency modulation.

The line of sight limitations of light could be an advantage in using it to convey information other than by vision. Suppose you are outside at night, or inside at any time. The white light from an ordinary incandescent light is a mixture of all colors. If we encoded information onto it the change would be scarcely noticeable, or not at all, to the unaided eye.

All that someone nearby would have to do is to activate an app that would utilize the phone camera. It wouldn't be a two way conversation but the light could provide all kinds of information tailored to that specific location, without going online at all. This wouldn't even use the internet or GPS. Since light would have bandwidth, due to it's higher frequency, there could be multiple channels of information.

The light in a waiting room could give people all kinds of information and, unlike radio waves sometimes, it would not interfere in the least with any light transmission outside the room. Streetlights could convey a lot of information, of interest of interest in that specific location, without using the internet or GPS at all. It wouldn't be difficult to mount a receiver on a vehicle that would automatically receive information as it passes streetlights.

Making it a two way conversation wouldn't be difficult at all. The phone has a flashlight. You could type a request onto a screen on the app and stand in front of a special receiver that uses photocells. A quick burst of light would convey your request. Again it wouldn't involve the internet or GPS.

The advantage of fiber optics for communication over electric current have long been known. How about the advantage of light over radio and microwave frequencies? Light wouldn't have the advantage in long range communication but it would in many instances of short range communication.