Researcher Build Optical Transistors

Well that was fast. On the back of other optical-related news comes this: a team from Purdue University has managed to make a transistor that parses data with light. This was the last logical piece of the puzzle needed for a fully optical transistor to be technically feasible, if not economically so. This architecture means that the computer could process data straight from a fiber optic cable, in addition to having significantly higher theoretical processing speeds than silicon processors.

This work builds on previous work, which had managed to build optical switches. In some ways, a transistor is just a fancy switch. In fact, wiring switches together can yield transistor-style logic. Many early computers were built that way. The problem with these early switches, however, was that the flow of light couldn’t act as the input for another switch. That has been fixed with this breakthrough.

Technology Review explains the new tech like this:

Their [Purdue’s] optical transistor consists of a microring resonator next to an optical line. In ordinary circumstances the light supply enters the optical line, passes along it and then outputs. But at a specific resonant frequency, the light interacts with the microring resonator, vastly reducing the output. In this state, the output is essentially off even though the supply is on.

The trick these guys have perfected is to use another optical line, called the gate, to heat the microring, thereby changing its size, its resonant frequency and its ability to interact with the output.

That allows the gate to turn the output on and off.

The tech isn’t yet ready for prime-time, however. Currently the optical transistor is both hard to produce and very power hungry. But then the first example of any tech is usually rough around the edges. With a little more development, we might start seeing the first optical computers within a decade. We’re going to need it, too, especially if the internet continues to become more concurrent and responsive.

Technology Review Photo by : Cornell University Library