[dogber1]

No, it won't: on the length scale of a chip, the power efficiency of an electrical-optical-electrical transmission line is an order of magnitude worse than direct electrical transmission, regardless of the actual technology. Also, optical transmission lines are huge in volume in comparison to electrical lines.

[thomasjames]

The article makes it seem like this technology will completely replace copper, which is obviously untrue. Silicon photonics for use in interconnects in multicores, though, is very promising purely from the perspective of bandwidth. HP and Intel have expressed interest, and there is a lot of academic research at Northwestern and UCSB ECE, for instance. I do not know what energy efficiency figures you were referring to, but emitter efficiency is dependent on the band gap and other properties of the semiconductor and lasing material, so the specific technology used does matter.

[colechristensen]

But light in free space travels 50% faster than electricity in copper and doesn't incur a heat load for the distance it travels. Likewise it carries more information than an electrical line.

Importantly as a counterpoint to

> the power efficiency of an electrical-optical-electrical transmission line is an order of magnitude worse than direct electrical transmission,

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> In contrast, semiconductors of main group IV — to which both silicon and germanium belong — can be integrated into the manufacturing process without any major difficulties. Neither element by itself is very efficient as a light source, however. They are classed among the indirect semiconductors. In contrast to direct semiconductors, they emit mostly heat and only a little light when excited.

>The scientists at Jülich’s Peter Grünberg Institute have now for the first time succeeded in creating a “real” direct main group IV semiconductor laser by combining germanium and tin, which is also classed in main group IV.