wrote in message
ups.com...
It was my understanding that the IR laser in a cd player is just too
"fat" in terms of wavelength to resolve the tin

That was where firefox crashed. I was going to say something about
tinier pits on DVD's..

When you say emits from one side or the other, do you mean that both
ends of the crystal are used as emitters? Or are there multiple diodes
in a single package? I never heard of this; it sounds interesting.

I just assumed that it was a single laser, but I have definitely
observed that a much more powerful looking beam is used to read DVD's
than CD's.


I actually tore apart a dual-wave diode a couple years ago, but I don't
remember exactly how it was built. I do remember it was roughly rectangular
in shape with tiny wires going to it. I only "presume" it was three
connections total, either 3 wires or two wires with a center common
connection.

Mark Z.