71–80 of 110 posts
Earlier quoted context omitted.
This comment appears insightful but I have no idea what it means. Can someone elaborate?
Electrons are fermions which means that two electrons can't occupy the same quantum state (Pauli exclusion principle). Bosons don't have the limit so I believe that implies that you can have stronger signals at the low end since you can have multiple photons conveying or storing the same information.
Earlier quoted context omitted.
You might be right and they are talking about fibre bundles, but that that's something different to a multicore fibre (and much larger as well, which could pose significant problems especially if we are talking cm links). What isn't addressed is that leds are quite spatially incoherent and beam divergence is strong, so the fibres they must use are pretty large, coupling via just a connector might not be easy especial…
> You might be right and they are talking about fibre bundles The caption of the image of the cable and connector reads: "CMOS ASIC with microLEDs sending data with blue light into a fiberbundle ." So yes, fibre bundles. > I don't see any advantage over vcsel arrays They claim the following advantages: 1. Low energy use 2. Low "computational overhead" 3. Scalability All of these at least pass the smell test. LEDs are…
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.
Earlier quoted context omitted.
> You might be right and they are talking about fibre bundles The caption of the image of the cable and connector reads: "CMOS ASIC with microLEDs sending data with blue light into a fiberbundle ." So yes, fibre bundles. > I don't see any advantage over vcsel arrays They claim the following advantages: 1. Low energy use 2. Low "computational overhead" 3. Scalability All of these at least pass the smell test. LEDs are…
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.
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.
That article is really low on details and mixes up a lot of things. It compares microleds to traditional WDM fiber transmission systems with edge emitting DFB lasers and ECLs, but in datacentre interconnects there's plenty of optical links already and they use VCSELs (vertical cavity surface emitting lasers), which are much cheaper to manufacture. People also have been putting these into arrays and coupling to multi-…
Earlier quoted context omitted.
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.
> 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 a…
Minor: It would be nice if the company TSMC is collaborating with on this, Avicena, is mentioned in the HN title.
Forgive the noob question but what stops us from making optical transistors?