"Plod's Conscience" wrote in message
ups.com...
Your underlying motivatiopn to pooh-pooh makes you
seem like a fool.


Someone offers you genuine information, on topic to your post, and you see
it as "pooh-pooh". I can see why you are a "slow learner", to use your own
description of yourself.

It is the optical path that determines the divergence, or otherwise
of the beam, by dispersion, diffraction, refraction mechanisms,
and not the coherence of the radiation.


Eh, no.

A laser will diverge in the absence of a medium.

Degree of collimation and coherence both are factors in divergence and you
are jumbling together a raft of factors that I supect you don't understand
and I know you don't want to learn about.

--
73
Brian
www.g8osn.org.uk