Yellow-green center

Researchers: This is what a single particle of light looks like

The image shows a photon with a yellow-green oval center surrounded by radiant blue light.

(Bild: University of Birmingham/Benjamin Yuen)

Researchers at the University of Birmingham have succeeded for the first time in visualizing the appearance of a single photon (light particle, note). The physicists achieved this with the help of a model that reconstructs the release of a photon from a nanoparticle more precisely and comprehensively than ever before.

The research team at the University of Birmingham in England has thus achieved a complete novelty in the field of physics. They were able to show in detail how the light particles are emitted by atoms or molecules and shaped by their environment.

The nature of this interaction means that light has an infinite number of possibilities to exist, spread or migrate in its environment, the scientists report in the journal "Physical Review Letters".

A challenge for quantum physicists
However, these unlimited possibilities make modeling the interactions very difficult and represent a challenge that quantum physicists have been working to overcome for several decades.

What is a photon?

A photon is the smallest possible form of energy in an electromagnetic field, which we know as light. The light particle is therefore a tiny packet of light energy. It has no mass and travels at the speed of light - around 300,000 kilometers per second.

According to the researchers in Birmingham, they were able to create a model that not only describes the interactions between the photon and the emitter (source of radiation or particle flow, note), but also how the energy from this interaction travels into the distant "far field". At the same time, they were able to use their calculations to create a visualization of the photon itself (see image above).

Image of photon is a "by-product"
"Our calculations enabled us to transform a seemingly unsolvable problem into something that can be calculated." And almost as a by-product of the model, we were able to create this image of a photon, something that has never been done before in physics," as the study's lead author, Benjamin Yuen from the Department of Physics and Astronomy at the University of Birmingham, explains. 

"This work helps us to improve our understanding of the energy exchange between light and matter and, secondly, to better understand how light radiates into its near and far surroundings," Yuen is quoted as saying. "Much of this information was previously considered just 'noise' - but it contains so much information that we can now understand and use," he said.