Introducing a transistor that can switch between two energy states

A team of engineers from the University of Illinois unveiled an upgrade to a transistor laser that can be used to increase computer processor speeds and form two stable energy states with the ability to switch between the two quickly.

Computers today are restricted by a delay that is formed as electrons travel through the wires and switches on the computer chip. To overcome this, engineers ideally seek to develop a computer that transmits data using light, rather than electricity, because light travels quicker.

Bistability, or having two stable energy states in a transistor, allows the device to form an optical-electric switch. The switch works as a component for the advancement of optical logic, the language needed for future optical computer processors to communicate, according to Milton Feng, the Nick Holonyak Jr. Emeritus Chair in electrical and computer engineering.

During the study, the engineers constructed optical and electrical bistable outputs from a single transistor. Adding an optical element builds a feedback look that uses electron tunneling, a process that controls the transmission of light.

The simple solution to solve the bottleneck formed by significant data transfer is to eliminate the electronic data transmission of the transmission and use all optics, but Feng noted that is very unlikely to occur.

“You cannot remove electronics entirely because you need to plug into a current and convert that into light,” Feng told Phys.org. “That’s the problem with the all-optical computer concept that some people talk about. It just is not possible because there is no such thing as an all-optical system.”

Before the study, Feng and Holonyak found that light, which was known as a byproduct of transistor electronics, can be used as an optical signal. This discovery opened the door for developing the transistor laser that uses light and electrons to send a signal.

The new transistor can implement new devices and applications not previously possible with traditional transistor technology. The team validated electro-optical bistability at –50°C. Their next step is to prove that the device can work at room temperature.

The published study can be found in the Journal of Applied Physics.

Via Phys.org