[nsteel]

Aren't they also claiming this is more reliable? I'm told laser reliability is a hurdle for CPO.

And given the talk about this as a CPO alternative, I was assuming this was for back plane and connections of a few metres, not components on the same PCB.

[topspin]

> Aren't they also claiming this is more reliable?

Indeed they do. I overlooked that.

I know little about microLED arrays and their reliability, so I won't guess about how credible this is: LED reliability has a lot of factors. The cables involved will probably be less reliable than conventional laser fiber optics due to the much larger number of fibers that have to be precision assembled. Likely to be more fragile as well.

On-site fabricating or repairing such cables likely isn't feasible.

[nsteel]

I understand that CPO reliability concerns are specifically with the laser drivers. It's very expensive to replace your whole chip when one fails. Even if the cables are a concern (I've no idea), having more reliable drivers would still be preferable to less reliable cables, given how much cheaper/easier replacing cables would be (up to a point, of course).

[topspin]

> I understand that CPO reliability concerns are specifically with the laser drivers.

Yes. I've replaced my share of dead transceivers, and I suspect the laser drivers were the failure mode of most of them.

That doesn't fill in the blank for me though: how reliable are high speed, dense microLEDs?

[nsteel]

And are they going to work out any better than Linear Drive Optics, the more obvious alternative?

[topspin]

LDO is just integration. It certainly has value: integration almost always does. So it's clearly the obvious optimization of conventional serial optical communication.

This new TSMC work with parallel incoherent optics is altogether distinct. No DSP. No SerDes. Apples and oranges.

[nsteel]

Ok, but I'm just after solutions to problems I have talking to other chips. I don't mind what's novel and what's optimisation. Whatever is adopted, in either case it's a step-change from the past 20 years of essentially just copper and regular serdes in this space.

And I'm not sure how much of this is actually TSMC's work, the title is misleading.

Edit: actually, they are working on the detector side.

[BardiaPezeshki]

we use borosilicate fibers that are used for illumination applications. You might have seen a bundle in a microscope light for example. And they are incredibly robust compared to single mode fibers. Note the very tight bend angle in the picture - that's a 3mm bend radius. Imagine doing that with a single mode fiber!

[topspin]

> And they are incredibly robust

See my other comment about non-datacenter applications. There is a serious opportunity here for fixing signal integrity problems with contemporary high bandwidth peripherals. Copper USB et al. are no good and in desperate need of a better medium.