BK> Well, with fibres you can transmit much faster than with electric wires. 

BK> thought maybe with a simple fibre network one could exceed the rates of
BK> ethernet. But while I think about it, some 100 MHz is about the maximum
BK> frequency todays electric circuits work with. So to get faster the 
process 
BK> to be parallelized like using multiple frequencies in the fibre which 
would
BK> require something like prisms and filters in the fibre connectors and 
would
BK> make the stuff too expensive for simple applications. And then, 100 Mbps 
is
BK> already as fast as todays hard disks. I only had the feeling of my 10 
bps
BK> ethernet.
Well, if you really wanted to get into how fast fiber optics transmit,
the 24 gigabit per second mark was broken in 1993 (according to one of
my old issues of LASERS and OPTRONICS) and I'm sure by now a few years
later, they have doubled that..  I havent seen too many really top notch
fiber optics systems for home useage, primarily because the technology
needed for very high speed communications is costly.. But I have seen
a few kits which sell for about $1,500 that can transfer data just about
as fast as any wired net used today.. (of course, the 24 gigabit data rate
I mentioned above, obviously neglects things such as the fact that the 
verage
computers today cant even output that, nor can disk drives, busses, etc..
There are not many reasons to justify setting up an optically linked system. 
the first good reason would be if yo wanted to run cable paths exceeding
1/2 to 3kilometers!!! which if you has a very large building with hundreds
of computers to wire on multiple floors, fiber would be the most wise choice, 
(if not the only real choice)..   Second would be if you have excessive 
amounts of electromagnetic interference in a particular area. If thats the
case, then they make very heavy duty shielded coax made especially for
high EMI enviroments, however this super-shielded cable is used mainly
for radio communications and may not meet the exact requirements for
computer network cabling.   Also, I think you asked what the receiver and
transmitting elements are composed of.  The coupler can be anything from
a cheap diode laser (a la' $30), to a very very expensive and specialized
laser costing hundreds (even thousands of dollars).  The LASERS used come
in a variety of frequencies, and obviously the more expensive lasers
use a higher frequency which optimizes the qualities of very expnesive
fiber optic cable. The cheap  opto-coupler systems (the ones with the
$30 diode lasers) are compatible with cheap FO such as plastic fiber
(which is much less expensive than glass fiber but also has much higher
path losses.)
If ya want exact specs, on different systems, the types of fiber needed,
etc.. lemme know, and I'll type up a list for you with some costs, etc..
--- GEcho 1.00
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