Increase the speed of telecommunications infrastructure by hundreds of times thanks to graphene

Recently, researchers at Bath University and the University of Exeter discovered that with several layers of graphene stacked, they could become a great material for optical switches, through which delivers transfer speeds 100 times faster than current telecommunications technology.

Optical switches are an important component in telecommunications infrastructure and although their performance is quite impressive, researchers have long argued that the layer of semi-metallic materials (including graphene) remains make them better.

Graphene and the next generation of telecommunications

When light hits a semiconducting semiconductor, energy causes the electrons to jump from a low energy state (valence band) through a small gap (the energy gap) into the state. higher energy (conduction band), in which electrons can move freely and conduct electricity. Finally, when the first energy is drained, the electron returns to its original state, through the energy gap back to the valence band.

To determine whether a material can be used to process information quickly, researchers need to learn more about how electrons move up and down between the energy gap in that material. The important factor is the time of recombination - the time it takes for an electron to make a loop from the conduction band to the valence band.

In recent years, researchers have improved the hypothesis that graphene can be an excellent material for the optoelectronic field. However, they have not been able to test their hypotheses because graphene is a semi-metallic substance or a "no-gap semiconductor" . In other words, there is no energy gap between the valence band and the conduction band. This means that it is difficult for scientists to effectively analyze its potential with current technology techniques.

The Bath team has found a way to measure the time of recombination in semi-metallic substances like graphene. Specifically, they measured how electrons move in the infrared spectrum of the spectrum and the shift of electrons between different quantum states. Through experiments, the skepticism of researchers has been demonstrated: while conventional optical switches respond at a rate of a few picoseconds (1 part per trillion of a second), physicists have Observe the reunification time of an optical switch using graphene layers of only 100 femtoseconds (1 femtosecond = 1 millionth of a second) - almost 100 times faster.

The discovery could open the door to a much faster generation of telecommunications and at the same time set an important step towards the development of cascading quantum laser technology (Quantum cascade laser or QCL) that could is used for many applications from remote sensing devices and pollutants in the environment, equipment for detecting chemicals in breaths, medical diagnostic tools to collision warning systems and Car navigation control.

Research by Bath and Exeter University was published in Physical Review Letters.