[c-nsp] Catalyst SX GBIC's and SMF

[Bill Wichers]

> On Mon, 10 Jan 2005, Bill Wichers wrote:
>
>> You should be safe using LX optics over multimode fiber. Mode
>> conditioning
>
> The original poster wanted to know if SX optics over SM fiber was ok (as
> stated in the topic).

Yes, I saw that just after writing and sending the first reply, unfortunatly.

A similar question was asked here several months ago, and I replied to
that one and will just summarize here... SX optics are *not* repliable
over singlemode fiber since they will not couple in enough light to work
reliably. I have seen it work over short distances, but would not
recommend it in a production network nor would I expect it to even come
close to the published distances SX will work over MMF.

The problems come from the SX optics being designed to couple light into a
much larger aperature (50-62.5 um) than SMF has (9-10 um). There are some
other issues from LED instead of laser light propagation in the fiber, but
the aperature size is a killer for performance in this case.

     -Bill

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Waveform Technology
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