Here’s The First-Ever Photo of Light Behaving as Both a Wave and a Particle

Quantum light
Fabrizio Carbone/EPFL

Researchers at the Swiss Federal Institute of Technology in Lausanne in Switzerland have captured the first photograph of light behaving as both a wave and a particle.

“This experiment demonstrates that, for the first time ever, we can film quantum mechanics—and its paradoxical nature—directly," Fabrizio Carbone, who led the research team that designed the technique to capture the breakthrough image, said in a statement. "Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing."

The team was able to capture the image by first shooting a pulse of laser light at a tiny metal wire, causing the light to travel in waves back and forth along the length of the wire. Then they fired a stream of electrons alongside the wire. The waves of light on the wire were made up of particles called photons, and when the electrons crashed into the photons, they either sped up or slowed down. The researchers used an ultrafast microscope, capable of seeing electrons, to capture a photograph of where change in electron speed occurred, resulting in an image of both the light in waves and in particles. “The changes in speed show up as energy blips that can be visualized,” the statement explained.

The lower layer of the image shows “packets” of energy exchange between electrons and photons, which results in a visualization of particles of light, while the top layer shows the wave-nature of the light, in “blips” of standing waves:

Quantum light Fabrizio Carbone/EPFL