Not famiiar with the Hitachi system, but it seems reasonable that with
regular LEDs you could only squeeze thru one channel or so of video. This
thing is broadband, and will pass a full 54-channel cable system. The
junction size & capacitance of laser diodes is so low that they can be
modulated beyond a gigahertz. Cool stuff. -joanne
Hey, for my ninth grade science project, I transmitted audio over an LED
beam… 🙂 It was quite simple; I connected the LEDs directly to the
output of an old amplifier, and connected a silicon solar cell to a second
amplifier, with focusing by a big Fresnel lens.
Funny, that's how I first tested the laser diode 🙂 I hooked it up
directly to the audio output of a tone generator and picked up the light
with a silicon cell…. low frequency response, but it's just fine for
audio! -joanne