Larry Dighera wrote in
:

On Wed, 5 Jan 2005 23:30:57 -0500, "Happy Dog"
wrote in : :

"Larry Dighera" wrote in message
. ..
On Thu, 06 Jan 2005 03:52:02 GMT, Jose
wrote in ::

There may not be that many photons involved, but
they are all coming from the same direction, and that does count for
something.

If I'm not mistaken, coherent laser light is all in phase. Doesn't
that cause it to have more energy?

No. The energy is measured in watts like any other kind of power
source.

I was referring to the phenomenon of light coherence. There's an
explanation of it he
http://whatis.techtarget.com/definit...id9_gci214527%
2C00.html

And my point was that because the light of a laser is coherent (in
phase), it will provide more energy than an equally bright light
source whose radiation is out of phase. At least this is what I was
told by an EE.




Coherence comes in two flavors. Spatial coherence add temporal
coherence. Spatial coherence is a measure of how well we can focus the
light into a small spot. Temporal coherence is a measure of how narrow
the frequency (color) is. Both are responsible for how it can damage the
eye. However, I doubt that a 5mW laser can cause much damage. I work
with these lasers all the time, but I have never looked at the beam
directly.