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204 points WithinReason | 1 comments | | HN request time: 0.218s | source
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yjftsjthsd-h ◴[] No.40712649[source]
So I guess what this makes me wonder is: Why are we using electrical signals to connect the data lanes between components and computers these days, rather than moving everything to optical for data movement (obviously power would stay electrical, but that's already on separate lines)? I assume there's an element of cost, and once the photons get where they're going they have to be turned back into electrical signals to actually be used until such time as we get around to getting pure light based computers working (someday but not yet...), but that must not overwhelm the advantages or we wouldn't be looking at this being developed.
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AceJohnny2 ◴[] No.40713112[source]
> I assume there's an element of cost, and once the photons get where they're going they have to be turned back into electrical signals to actually be used until such time as we get around to getting pure light based computers working (someday but not yet...)

You got it. We can't make optical transceivers as good as electrical ones. Not as small or power-efficient.

They require significantly different fabrication processes, and we don't know how to fab them into the same chip as electrical ones. I mean: you can either have photonics, or performant digital (or analog) electronics.

We've gotten really, really good at making small electronics, per the latest tech coming out of Intel & TSMC. We are... not that good at making photonics.

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1. thmsths ◴[] No.40717909[source]
This sounds like something that could help us become really good at photonics though. The major issue when trying to displace the good old silicon transistors is that we have invested so much in the tech and they are just so good that competing technologies with higher potential but starting at the bottom of the S curve are simply not competitive. PCIe is widely used, if it switches to photonics, despite the current shortcomings this is very encouraging for photonics.