Optical Computing Feasibility

Theoretically? Yeshttps://en.m.wikipedia.org/wiki/Optical_computing

Do optical computing need to use visible light?

I can't read the article as it's behind a paywall, but if you can make a chip that's 100% optical, then it means that when you beam your input data at the input end of the chip, you _instantly_ get the output at the end. No need for cycles for multiplying, adding and so on. Plus it wouldn't heat up like silicon does.

It's actually highly inefficient to do (general) computation with photons. In contrast to electrons, photons really don't like to interact so you need a lot of optical power to implement an optical transistor-like, this was studied by Prof. David Miller some time ago (doi:10.1038/nphoton.2009.240, I think this is the correct citation am on the phone right now). Like others said, the device proposed in the paper here is more like an analog computer (with ML they have really seen a

Optical computation will never become relevant at scale. There are fundamental reasons for this: first, particle size. A photon at usable wavelengths is extremely large, much larger of any modern electron based _devices_ This makes it imossible to scale to usable density. Second, optic-optic (as opposed to electro-optic) non linear effects are based on interaction with electrons, in particular with electron decay from an energy state to another which is tipically extremely slow.

No this is not an engineering issue, it's a problem of fundamental physics. Photons don't interact easily. That doesn't mean there are not specialised applications where optical processing can make sense, e.g. a matrix multiplication is really just a more complex lens so it's become very popular to make ML accelerators based on this.

Do we even have an optical transistor yet?

Optical computing would be pretty cool.

I think it is called "optical computing".

Any updates on the optical CPU front?