On Apr 17, 2:57 pm, Richard Clark wrote:
....

Richard, it really doesn't much matter to me what modes fiber optic
cable supports. If there are types that support true TEM mode, I'd be
happy to hear about it. So far, though, I've followed links from over
a dozen searches and found NO reference that claims that true TEM mode
is supported by a fiber, be it single-mode or multi-mode. I've gone
to the Wikipedia pages you suggested and other pages there, and found
quite a bit of info about fiber optic cables and their modes. In all
that, I have found no claim that true TEM mode is supported. I
followed the link you provided to the simulation software provider,
and found only that they modeled a particular cable as having TEM 0,0
mode; nowhere could I see a claim that the cable modeled actually
propagates by true TEM mode. The way the article was worded sounded
to me like the TEM entry was an approximation. In my research, the
closest to a claim of true TEM mode I've found has been in one recent
article that says TEM would be the ideal, but the best anyone's been
able to do is quasi-TEM or TEM-like.

You're welcome to think it's true TEM if you wish, of course, but your
saying it, over and over if you wish, isn't going to be nearly as
convincing as if we can find one, even one, ligitimate reference that
claims true TEM.

Cheers,
Tom