guitar pick-ups infrared/optical

[The Dong]

Paul Maddox wrote:
> Nice idea, shame about the cost though :-)

I wonder how easy it would be to make a pickup like this?
I guess not very hard, as it's just infra-red LED's and photo 
transistors and amplifiers. Some filters/E.Q..

In any case, an optical pickup replacement for a guitar or bass should 
be cheaper than the clunky, standard wound PU, simply because it is less 
expensive to create. But in reality.....