Does such thing exist ? Modulating a laser or led with NTSC for over-the-air link, a few watts... (not fiber optics)

 

Does such thing exist ? Modulating a laser or led with NTSC for over-the-air link, a few watts... (not fiber optics)

Should be possible with a fast LED and photodiode detector. Phototransistor will be too slow as a detector.

 

Thanks. There is something in youtube; NTSC modulating a white led; but with zero details and the amount of garbage published there, there is little to believe. Not that is not possible, but would like to learn about it.

 

You would need the optical link to have at least a 5MHz response.
The composite video signal would need a DC bias so that the optical signal can transmit both the plus and minus portions of the video.

 

Thanks. There is something in youtube; NTSC modulating a white led; but with zero details and the amount of garbage published there, there is little to believe. Not that is not possible, but would like to learn about it.

Yes, I would agree it is garbage. The last thing you want to do is transmit a signal on white light. This makes it impossible to filter out ambient light.

There are commercial products that use fiber optics. Do a search for this: ntsc over fiber . Be prepared for sticker shock.

I doubt that there is a product for through-the-air transmission. I would think you could make something but as @crutschow says the bandwidth requirement is going to make it tricky. You might end up using avalanche diodes for the receiver.

 

Thanks, gentlemen.
Tried to attach a schematic but the plug-in crashed. Perhaps another day will work.