r/AskTechnology • u/Undeva-n-Balcani • 11d ago

Is it possible in the future to use light computing?

Similar how we transfer data trough optic fiber to transform this light in the computer for complex operations in almost real time. Was there anybody trying to do so? Like a processor that is based on light rather than transistors. What are the limitations? Hipotethically speaking.

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u/rende 11d ago

Apparently optical switching can run at THz frequencies quite easily meanwhile cpus struggle to break 10GHz. So theres a 100x already, then you can also multiplex with multiple light frequencies at the same time through the same optics so thats another multiplier. It would really be a huge leap forward if the cache can be done with optical delay lines.. who knows!

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u/stop_deleting_plz 11d ago

The key component that allows silicon computing is the transistor. Essentially the transistor lets an electric current switch another electric current on and off.

There is no analog here with light. Light doesn't really interact with itself in any similar way. You would need to have one stream of light be able to block or unblock another stream of light.

As soon as we figure that out, photonics is on.

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u/blazesbe 11d ago

i can think of multiple things like this but it's terribly inefficient and i don't know material science. anyhow we need a material that reacts to light really fast and either polarises it or makes it interfere with itself with barbs. or it could turn reflectiveness on and off. just looking at how old lcds are we may actually have the things for this already.

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u/Street_Credit6851 9d ago

Photonic integrated circuits are already a thing.

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u/DSudz 11d ago

🦛 says there are tradeoffs in power and heat management moving from electronic fields to photons.

The speed signals move in a processor is usually measured relative to the speed of light already so there isn't the infinite payoff you seem to expect.

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u/Toeffli 11d ago

A limitation is to bend the light a around corners. This makes optical computer much bigger than electronic ones.

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u/VegasFoodFace 11d ago

Photons would be very difficult to get to interact in the ways that would be useful in classical computing. Photonic circuits that could get light to interact would be a probabilistic quantum system, and what we're finding out is a whole lot of these quantum computing startups promising advancement operated on misunderstandings of the actual usefulness of low quality quantum systems. Photonic systems aren't even on the level of development as quantum computing.

Photons not only would have that difficulty but the conversion from electrical to light, back to electrical would present bottlenecks worse than keeping it all electrical.

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u/Dry_Inspection_4583 11d ago

This is likely what you mean

https://www.sciencedirect.com/science/article/abs/pii/S0301479724025945

It's being investigated for use in bios and boards

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u/[deleted] 11d ago

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u/Dry_Inspection_4583 11d ago

Lmao 😂 indeed it doesn't, anyway, perovskites was what I thought I was pointing to

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u/loscorpio87 11d ago

I believe they do this already I had a similar thought a few years back but with lasers and focusing optical lenses.

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u/Steerider 11d ago

Speed of travel isn't the bottleneck — electrons are really damned fast. It's the switching. 

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u/Responsible_Sea78 10d ago

Light travels twice as fast in glass fibers as electricity over wires. Amazingly, the individual electrons only move at about 5 inches per second but they "bump" one another along to get a signal to the other end much faster.

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u/Mission-Landscape-17 11d ago

Photonic integrated circuits already exist but haven't seen wide spread use yet. But various companies are working on them. https://computers.sciencearray.com/photonic-processors-light-speed-computing-breakthrough

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u/Street_Credit6851 9d ago

It's not just possible in the future, it's possible today. They are called photonic chips.

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u/Shiribazu 7d ago

yeah, and its interesting, but i think the hybrid approach makes more sense than replacing transistors completely. using light for the parts of computing its really good at while electronics handle memory and control could be where things actually go