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.