Optical computing

Optical computing, also known as photonic computing, uses light waves from lasers or other light sources to help with tasks like storing and moving information for computing. Unlike regular computers that use tiny particles called electrons to process data, optical computing uses photons, which can move much faster and carry more information at once.

Scientists and engineers have studied this idea for many years because light can carry more information than electricity. Right now, most projects try to replace some parts of regular computers with optical parts. This creates a mix of both light-based and electric parts, which can make computers work better. But turning information from light back into electricity takes a lot of energy and can slow things down.

Some special tools, like synthetic-aperture radar and optical correlators, already use ideas from optical computing. These tools can help find and follow objects, as well as sort through lots of information very quickly.

Optical components for binary digital computer

The basic part of today’s electronic computers is called a transistor. Scientists are working on making similar parts using light instead of electricity. They use special materials that change how light passes through them, acting like tiny switches. These light-based switches can be used to build the basic parts of a computer, such as logic gates, which help control how information flows.

An optical computer needs a few important things to work well: a way to process information with light, cables to move information, a place to store information, and a light source like a laser. However, changing information between light and electricity can slow the system down. Some people wonder if these light-based computers will ever be as fast or efficient as today’s electronic computers. They say big new discoveries in light-based technology might be needed to make them work better.

Main article: optical transistor
Main articles: optical logic gate, central processing unit

Challenges

One big challenge for optical computing is that light needs help from special materials to work well together, unlike the parts in regular computers. Because of this, optical computers might need bigger and stronger parts to do the same jobs.

Even though light can move faster than the tiny parts inside today’s computers, there are limits to how fast optical parts can switch on and off. These limits come from the natural rules that control light, making it hard to make optical computers much faster than the ones we use now.

Photonic logic

Photonic logic uses light to perform important thinking tasks in computers. By combining light signals in special ways, scientists can create tiny tools called logic gates that help computers make decisions.

Special tools called resonators help make this work better by building up light energy. Researchers have also looked at using tiny molecules that glow when light hits them to do these tasks.

Unconventional approaches

The idea behind this type of computing is to use delays in light signals to solve difficult problems. Light can be delayed by passing it through special glass fibers and can also be split into multiple rays. This allows scientists to check many possible solutions at once.

Researchers have used light to solve various problems. For example, they can create structures with optical cables and splitters to guide light and mark when it passes through certain paths. By watching for specific signals at the end, they can find solutions to complex questions. Other methods include using the properties of light waves, such as different colors, to represent information. Some experiments even use simple tools like photocopiers and transparent sheets to perform calculations by overlapping copies of information. These unusual approaches show how light might one day help computers solve problems faster.

Main article: NP-complete problems

Main articles: convolutions, attention, tensor

Further information: Ising model

Industry

Many companies are working on developing optical computing. These include well-known tech companies like IBM and Microsoft, as well as newer firms such as Procyon Photonics, Lightelligence, Lightmatter, Optalysys, Xanadu Quantum Technologies, Q/C Technologies, QuiX Quantum, ORCA Computing, PsiQuantum, Quandela, TundraSystems Global, and Q.ANT. These companies are exploring ways to use light for faster and more efficient computing.