Guided transmissions
Comparison of optical and electrical links

In the optical field, unlike the electrical field, there are several modes of propagation in the guide, depending on its dimensions (see the article Optical interconnections [E 3 652] in this treatise):

• when the cross-section of the guide is of the order of a few wavelengths, we speak of a single-mode guide;

• when the cross-section is much larger, we speak of a multimode guide.

As we have already shown, single-mode optics offer the best performance in terms of bandwidth and linear attenuation, while multimode optics offer the best...