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Optical computing streamlined with garnet filters

Optical computing streamlined with garnet filters


Researchers at MIT have developed a "light diode" — a crucial step in the development of optical computing.

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New technology that channels light in the same way that diodes direct electrons could be the future of optical computing. While optical systems are much faster than their electronic counterparts, they are generally limited by higher costs and the need for additional equipment to control interference. These so-called isolators add to the complexity of the design, but an MIT team has figured out a way to achieve the same noise-reducing effect more simply.

Diodes form a critical part of any circuitry since they allow electrons to pass only in one direction, which creates the potential for logic gates. Without the isolators, reflections of the laser (or LED) inside the chip can cause interference and corruption. MIT's solution to this uses a thin film of garnet over the optical receiver, preventing feedback within the chip. Garnet's high refractive index means that any light not entering the film directly will be bounced back into the loop.

The technology makes all-optical computing a more feasible possibility. As Professor Caroline Ross told MIT News, “just like an integrated-circuit person can design a whole microprocessor, now you can do an integrated optical circuit." Additionally, because the chips are silicon-based, current manufacturing methods can still be used. As always with technologies like this, commercialization is a way off, but the technology behind it could define the next generation of communications.