Scientists Create the Shortest Pulses of Visible Light Ever Made in a Lab

Light Speed Computers?

Scientists from across the globe are trying to understand the link between photons and electrons, working in the hopes that the former will one day replace the latter in high speed computing. Ultimately, this led to the study of what happens when photons come in contact with electrons that remain in their respective atoms, and how long it takes for electrons to respond to these beams of light.

Now, researchers hailing from Germany, the U.S., and Russia have developed a method of measuring the amount of time it takes for an atom’s electron to respond to a light pulse.

Ultimately, they were able to do this using a pulse of light that is just 380 attoseconds long – 380 x 10^-18 seconds (1 attosecond is equal to 1 quintillionth of a second). These flashes are the shortest pulses of visible light that we have ever created in a lab.

In their work, the research team describes how they use a light-field synthesizer (which is a device that can create pulses of light that are only half as long as a single wavelength) to produce pulses of light that are fast enough to reveal to time it takes for electrons to respond when they are struck.

Their findings have been published in a paper in the journal Nature.

 

How it Works

The light-field synthesizer combines several pulses of light that are slightly out of phase. This allows for canceling, leading to one very short pulse of light. In the paper, the team asserts that they fired these short pulses at krypton atoms that are held in a vacuum.

In short, theories suggested that electrons take a few hundred attoseconds in order to kick out a fresh photon after they’ve been hit by an incoming beam, but the precise figure was unknown. In a scientific first, the researchers found that it takes electrons 115 attoseconds to respond to the light pulses.

The research team says it will continue to look at how electrons in other materials will behave when subjected to the light-field synthesizer. They also aim to characterize the amplitude and phase of radiation from atoms that are driven by a light field. Hopefully, this work will help us better understand the processes that may lead to better computing technology.