It is. But it’s not the only possible waveguide. The article discusses alternatives for a system that can transmit 5-10k signals in 32U. If you’re using fiber optic cables, that’s 5-10k pairs, in 32U. That doesn’t work at all. It’s light (ha, pun) on details for what the alternative waveguide is, though.

Just getting VCELs to 25G per lane would be nice, though, if you can match current prices. Upgrading to 100G-SR4 on the same cable plant would be nice.

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nullc 4 days ago | parent [-]

> If you’re using fiber optic cables, that’s 5-10k pairs, in 32U.

not with 4 or 12 core MCF!

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deepnotderp 4 days ago | parent | next [-]

MCF has a bunch of challenges, eg no good pigtail connector, need for rotational alignment, inability to radix (MCF is great for point to point, less good if you want to fan out from one chip to multiple chips), etc

And then even after all that, it’s still 1-2 orders of magnitude lower density than waveguides

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bc569a80a344f9c 4 days ago | parent | prev [-]

Fair! Would still be a nightmare to manage, though. I wish they had some details on the proposed alternative waveguide.

	▲	DarkSucker 4 days ago \| parent [-]
		I think the alternative is shown in figure 2. SiN (silicon nitride) is different from optical fiber. Both versions shown in figure 2 lack detail, especially in the small boxes labeled GC, Mirror, and PD. Depending on the details, one might put micro optical assemblies between or in those boxes in the figure. In any case, SiN waveguides are small, so you can pack many lanes in a small space.