Can you explain what multi-mode fibres are? From what I've read, it allows for WDM over a single fibre. But what is physically different about these multimode fibres that allow for this Space-division multiplexing? Wikipedia says:

>Multi-mode fiber has a fairly large core diameter that enables multiple light modes to be propagated and limits the maximum length of a transmission link because of modal dispersion.[0]

But that's clearly wrong because here we are using the standard diameter.

[0]https://en.wikipedia.org/wiki/Multi-mode_optical_fiber