- "The new gates performed at speeds of less than 100 femtoseconds, which is roughly 1 million times as fast as electronic gates"
Electronic gates switching at 10 MHz?
Electronic gates switching at 10 MHz?
There are other serious technical errors in the piece too. For example they say "because photons move at the speed of light and electrons don't" ... which is irrelevant because electronic signals do move at the speed of light.
The most serious problem is missing context. It's been known for decades that you can build shockingly fast optical switches and even amplifiers. A hundred fs is fast but not unique. The problem is how to connect these devices in a complicated circuit without putting nanoseconds of waveguide in between. Unfortunately 1 ns is 1,000,000 fs.
So in telecom, where you're just going a long way in one direction, optical amplifiers with multi-THz bandwidth have dominated transport since the 1990s. But in computers, no.
For starter, for electron you have contention in the form of collision but there's no collision for photon. Imagine you have vehicles that can go pass through each other without any collision, they will be exponentially faster than the one's without this capability.
[1]Two Startups Are Bringing Fiber to the Processor:
https://spectrum.ieee.org/optical-interconnects
[2]Power and Latency Analysis of the Memory Tiering Pyramid: The CXL Effects:
Collisions between electrons don't directly affect either picture. You can multiplex lots and lots of completely independent 'electronic' EM waves on one conductor, they pass right through each other exactly as you described for optics, no problem.
The advantage of optics is that the low-loss bandwidth of optical waveguides is enormously wider than the low-loss bandwidth of waveguides made using copper or other conductors. And with optics we have enormous bandwidth available.
One disadvantage of optics is that we don't have a low-lag way to interconnect switches. We can connect switches, but so far the interconnect delays are much, much longer than the switching times. So a fast optical switch is useful, but so far only in systems that are solely "feed forward," like communication.
> "Since light oscillates so fast (roughly a few hundred million times per second), using light could speed up electronics by a factor of roughly 10 000 as compared to computer chips,” says Tobias Boolakee, a laser physicist in Peter Hommelhoff’s group at the FAU and the first author of a study in Nature on the new gate." (2022)
For anybody who doesn't juggle large numbers every day, a hundred million is 1e8. Ten to the eighth.